GIFT  OF 
Mrs.    John  B.   Casserly 


SCIENCE  FOR  THE  YOUNG; 

OR, 

THE  FUNDAMENTAL   PRINCIPLES  OF  MODERN  PHILOSOPHY 
EXPLAINED  AND  ILLUSTRATED 

IN 

40 

CONVERSATIONS  AND  EXPERIMENTS, 

AND   IN 

NARRATIVES  OF  TRAVEL  AND  ADVENTURE  BY  YOUNG 
PERSONS  IN  PURSUIT  OF  KNOWLEDGE. 


VOL.  I— HEAT. 


THE   DOINGS    OF   HKAT. 


SCIENCE  FOE  THE  YOUNG. 


HEAT 


Bv  JACOB  ABBOTT, 


n 

AUTHOR  OF 


'THE    FRANCONIA   STORIES,"    "MARCO   PAUL   SERIES,"    "YOUNG 

CHRISTIAN    SERIES,"    "HARPER'S    STORY   BOOKS," 

"ABBOTT'S  ILLUSTRATED  HISTORIES,"  &c. 


WITH  NUMEROUS  ENGRAVINGS. 


NEW    YORK: 

HARPER  &  BROTHERS,  PUBLISHERS, 


FRANKLIN     SQUARE. 


by 


Entered  according  to  Act  of  Congress,  in  the  year  1871,  by 

HARPER   &   BROTHERS, 

In  the  Office  of  the  Librarian  of  Congress,  at  Washington 


OBJECT  OF  THE  WOEK. 

THE  object  of  this  series,  though  it  has  been  prepared 
with  special  reference  to  the  young,  and  is  written  to  a 
considerable  extent  in  a  narrative  form,  is  not  mainly  to 
amuse  the  readers  with  the  interest  of  incident  and  ad- 
venturej  nor  even  to  entertain  them  with  accounts  of  cu- 
rious or  wonderful  phenomena,  but  to  give  to  those  who, 
though  perhaps  still  young,  have  attained,  in  respect  to 
their  powers  of  observation  and  reflection,  to  a  certain 
degree  of  development,  some  substantial  and  thorough 
instruction  in  respect  to  the  fundamental  principles  of 
the  sciences  treated  of  in  the  several  volumes.  The  pleas- 
ure, therefore,  which  the  readers  of  these  pages  will  de- 
rive from  the  perusal  of  them,  so  far  as  the  object  which 
the  author  has  in  view  is  attained,  will  be  that  of  under- 
standing principles  which  will  be  in  some  respects  new 
to  them,  and  which  it  will  often  require  careful  attention 
on  their  part  fully  to  comprehend,  and  of  perceiving  sub- 
sequently by  means  of  these  principles  the  import  and 
significance  of  phenomena  occurring  around  them  which 
had  before  been  mysterious  or  unmeaning. 

In  the  preparation  of  the  volumes  the  author  has  been 
greatly  indebted  to  the  works  of  recent  European,  and 
especially  French  writers,  both  for  the  clear  and  succinct 
expositions  they  have  given  of  the  results  of  modern  in- 
vestigations and  discoveries,  and  also  for  the  designs  and 
engravings  with  which  they  have  illustrated  them. 


75690 1 


CONTENTS. 


CHAPTEB  PAOK 

I.  THE   GREAT  DEVOURER 13 

II.  LIFE,  DEATH,  AND    DISSOLUTION 22 

III.  GOING   ON   BOARD 33 

IV.  LEAVING   PORT 48 

V.  COMBUSTION 55 

VI.  FLIPPY  A   REFEREE 63 

VII.  THE    FIRE    IN   THE    STREET  .  . 72 

VIII.  THE   THREE   RECAPITULATIONS 79 

IX.  ENORMOUS  FORCE 92 

X.  TRACKS   OF   THE   STEAMERS 107 

XI.  WHAT   IS   SMOKE? 116 

xii.  THE  "  FIDDLE" 124 

XIII.  BURNING   OF   IRON 132 

XIV.  FLAME 138 

XV.  THE   BANKS   OF   NEWFOUNDLAND 147 

XVI.  MISS   ALMIRA 157 

XVII.  MEASUREMENT   OF   HEAT 169 

XVIII.   PERSONALITIES 181 

XIX.  THE   ICEBERG 189 

XX.  THE   WORK   OF   THE   ARCTIC   ICE 198 

XXI.  HEAT  A  FORM   OF   FORCE 208 

XXII.  THE   MECHANICAL   EQUIVALENT   OF   HEAT 214 

XXIII.  THERMOMETERS 224 

XXIV.  FORCE   CONVERTED    INTO    HEAT 230 

XXV.  THE   THERMO-ELECTRIC   MULTIPLIER 240 

XXVI.  TRANSMISSION   OF   HEAT 247 

XXVII.   SCIENTIFIC    TERMS    EXPLAINED 259 

XXVIII.  THE    SEA-BIRDS 273 

XXIX.  OXYGEN   AND   THE   TELEGRAPH 284 

XXX.   JUMPING   TO    GREENWICH    TIME 292 

XXXI.   END    OF   THE    VOYAGE 297 

A  2 


ILLUSTRATIONS. 

Page 

The  Doings  of  Heat Frontispiece. 

Breakfast-room  at  the  Hotel 16 

Producing  Oxygen 23 

Tropical  Forest 30 

The  Embarkation 42 

The  State-room 46 

Fusion  and  Combustion  of  a  Hydrocarbon 52 

The  Candle  Flame 67 

Fire  in  a  Street 76 

On  Deck 84 

A  Furnace  Room  at  Sea 100 

An  Engineer  at  his  Post 114 

Smoke 122 

Going  down  by  a  Tub 128 

Combustion  of  Iron 136 

Filling  a  Retort 140 

Gas-holder 141 

Icebergs  depositing  Rocks 148 

The  Argand  Burner 152 

Going  down  by  Ladders 156 

Coal-miner  at  Work 159 

Ancient  Vegetation  (Ideal  Landscape) 164 

The  Stored  Force  recovered 167 

Quantity  of  Heat 179 

An  Arctic  Glacier 192 

The  Iceberg 195 

Outgoing  and  Incoming  Currents 205 

Joule's  Apparatus 216 

Heat  derived  from  Force  of  Friction 218 

Heat  converted  into  Expansive  Force 219 

Walls  brought  up 220 

The  heated  Ball 220 

Self-registering  Thermometer 225 


Xii  ILLUSTRATIONS. 

P«g« 
Differential  Thermometer 227 

Effect  of  Diminished  Friction 235 

The  Waterfall  (Nevada  Fall) 237 

Melloni's  Thermo-electric  Multiplier 241 

Adventures  among  the  Alps 245 

Effect  of  the  Concave  Reflector 249 

Cooking  by  the  Reflected  Heat  of  the  Sun 250 

Effect  of  the  Convex  Lens 252 

Conduction  of  Heat 252 

Leslie's  Cube 256 

The  Noon  Gun  of  the  Palais  Royal 257 

Explosion  in  a  Coal-mine 261 

Explosion  in  a  Foundery 264 

Explosion  in  a  Laboratory 265 

The  Ice-chest 268 

The  Cake  of  Wax 268 

Learning  to  Draw 277 

Horse-shoe  Electro-magnet 286 

Action  of  the  Telegraph 287 

Combustion  of  Zinc 299 

Volcanic  Submarine  Eruption  (Volcano  of  Santorin) 301 

The  Sun  and  his  Work 303 

The  Alarm  of  Fire...  307 


CHAPTER  I. 

THE    GREAT   DEVOURER. 

LAWRENCE  and  his  cousin  John  were  sitting  at  a  table 
together  in  the  breakfast-room  of  a  large  hotel  in  New 
York,  waiting  for  their  breakfast  to  be  brought  in.  After 
breakfast  the  coach  was  to  come  which  was  to  take  them 
on  board  the  steamer  Scotia,  in  which  they  had  taken  pas- 
sage for  Europe.  The  steamer  was  to  sail  that  day  at 
eleven  o'clock,  and  it  was  now  about  eight.  The  coach 
was  expected  at  half  past  nine. 

"  I  am  glad  we  are  going  in  an  iron  steamer  instead  of  a 
wooden  one,"  said  John.  "  We  are  safe,  at  any  rate,  from 
being  burnt  up  on  our  voyage,  though  we  may  get  blown 
up." 

"  And  yet,"  replied  Lawrence, "  iron  is  more  combustible 
than  wood." 

"  Oh,  Lawrence  !"  exclaimed  John. 

John  was  only  about  thirteen  years  of  age,  but  Lawrence 
was  over  twenty,  and  he  had  just  completed  his  studies  at 
a  scientific  school  in  New  Haven.  His  head  was,  conse- 
quently, very  full  of  scientific  ideas,  and  his  talk  of  scien- 
tific words. 

"Perhaps  I  am  wrong  in  saying  exactly  that,"  added 
Lawrence.  "  I  am  not  sure  that  I  know  precisely  what  is 


14  THE    GREAT   DEVOUKEK. 

implied  by  a  thing's  being  more  or  less  combustible.  What 
I  mean  to  say  is  that  it  is  more  strictly  and  completely  true 
that  iron  is  combustible,  than  to  say  that  wood  is." 

"  But,  Lawrie,"  said  John, "  that  can  not  possibly  be  so ; 
for  iron  is  not  combustible  at  all.  You  can  heat  it  red  hot 
without  its  taking  fire.  Besides,  if  it  is  combustible,  how 
ijs'it  thai  thb^n|y£do  not  take  fire  when  we  take  up  burn- 
ing coals* witS  them^.and  how  can  they  make  andirons  of 
*|  ai^^yfSj  iny|U  grates?  I'll  bet  you  any  thing  that  it 
is  not  combustible." 

"  What  will  you  bet  ?"  asked  Lawrence. 

"  I'll  bet  you  an  orange,"  said  John, "  to  pay  when  we 
get  on  board  the  ship." 

"  But  we  can  have  as  many  oranges  as  we  want  on  board 
the  ship,  just  for  the  asking,"  said  Lawrence. 

*'  Then  I'll  bet  you  a  pound  of  grapes,"  said  John, "  when 
we  get  to  Paris." 

"  Done,"  said  Lawrence ;  "  and  whom  shall  we  leave  it 
to?" 

Just  at  this  moment  the  waiter  appeared,  bringing  the 
breakfast.  It  consisted  of  coffee,  hot  rolls  and  butter,  a 
beefsteak,  and  some  boiled  eggs.  The  boys  paused  in  their 
conversation  to  watch  the  movements  of  the  waiter  in  ar- 
ranging these  things  upon  the  table.  Their  minds,  too, 
were  occupied  in  agreeable  anticipations  of  the  pleasure 
of  having  so  good  a  breakfast. 

It  may  seem  rather  disrespectful  to  Lawrence  to  desig- 
nate him  as  a  boy,  but  the  major — a  gentleman  who  was 
going  to  make  the  voyage  with  them,  and  who  was  a  rela- 
tive of  theirs — having  been  accustomed  to  call  Lawrence 
and  John  both  boys  when  they  were  younger,  still  contin- 
ued the  practice,  and  I  shall  take  the  same  liberty,  on  ac- 
count of  the  convenience  of  it. 

When  the  waiter  had  arranged  every  thing  properly 


FLIPPY.  1 7 

upon  the  table,  he  lifted  the  cover  from  the  beefsteak  and 
went  away. 

"  We'll  leave  it  to  the  major,"  said  John. 

"  This  is  a  nice  steak,"  said  Lawrence. 

The  steak  did  indeed  look  very  nice,  as  it  lay  in  the 
midst  of  its  rich  gravy  upon  the  oval  dish.  Lawrence  took 
up  a  knife  and  fork  and  began  to  divide  it  into  two  parts, 
in  order  to  put  one  part  upon  a  plate  for  John. 

"  On  the  whole,"  said  he,  after  he  had  given  John  his 
portion  of  the  steak,  and  had  also  poured  him  out  a  cup  of 
coffee — "  on  the  whole,  I  think  we  will  give  up  the  bet.  It 
is  not  a  good  plan  to  make  bets.  I  will  explain  to  you 
how  it  is  that  iron  is  more  strictly  and  completely  combus- 
tible than  wood,  and  then  you  can  judge  for  yourself.". 

"  Yes,"  replied  John, "  that  will  be  better." 

Just  then,  in  looking  up,  John's  eyes  fell  upon  the  figure 
of  a  boy  a  little  younger  than  himself,  who  was  standing 
at  the  door.  As  soon  as  he  saw  John  looking  at  him,  he 
began  to  make  up  laughable  faces  at  him  and  perform  va- 
rious antics,  without,  however,  making  any  noise,  so  that 
he  did  not  attract  the  attention  of  any  body  else  in  the 
room. 

"  Ah !"  said  John, "  there's  Flippy." 

"  Flippy  !"  repeated  Lawrence.    "  That's  a  funny  name." 

"  Well,  he's  a  funny  fellow,"  said  John, "  and  he  ought  to 
have  a  funny  name." 

"  But  what  is  his  real  name  ?"  asked  Lawrence.  "  Flippy 
is  no  name  at  all." 

"  I  don't  know  what  his  real  name  is,"  said  John.  "  They 
call  him  Flippy.  And  he  is  going  with  us  across  the  At- 
lantic." 

"  That  is  good,"  said  Lawrence ;  "  for  now  you  will  have 
a  playmate  on  board." 

During  this  conversation  John  had  beckoned  to  Flippy 


18  .         THE    GREAT   DEVOUEER. 

several  times  to  come  to  them.  Flippy  had,  however,  taken 
no  notice  of  this  invitation,  but  still  stood  in  the  doorway. 
He  was  rather  short  and  thick  in  form,  but  his  countenance 
was  frank  and  open,  and  it  wore  a  good-natured  and  rather 
pleasing  expression. 

Lawrence  thought  at  first  that  the  reason  why  Flippy 
did  not  come,  in  compliance  with  John's  beckoning,  was 
that  he  was  afraid.  But  he  soon  found  that  bashfulness 
was  not  the  cause  which  kept  him  back,  for,  after  waiting 
a  moment,  he  suddenly  walked  in,  apparently  entirely  at 
his  ease,  and  came  through  the  room  to  the  table  where 
Lawrence  and  John  were  sitting. 

"  I  wish  my  breakfast  was  ready,"  said  he.  "  I've  got  a 
devouring  appetite." 

"  That's  right,"  said  Lawrence.  "  You  had  better  have 
a  good  appetite  now,  for  I'm  afraid  you  will  have  very  lit- 
tle after  you've  been  at  sea  twenty-four  hours.  Do  you 
think  you  could  devour  a  large  piece  of  beefsteak  this 
morning  ?" 

Flippy  said  he  could ;  and  then  Lawrence  asked  him  and 
John  what  they  thought  was  the  greatest  devourer  in  the 
world. 

"  Is  it  a  conundrum  ?"  asked  Flippy. 

"  No,"  said  Lawrence, "  it  is  a  serious  question." 

"  I  wish  it  was  a  conundrum,"  said  Flippy.  "  I  can  guess 
conundrums  first-rate." 

"  No,  it  is  not  a  conundrum,"  repeated  Lawrence ;  "  it  is 
a  serious  question." 

"  The  lion,"  said  John,  guessing. 

"  No,"  said  Lawrence.  "  The  lion  is  a  great  devourer, 
but  not  nearly  so  great  as  the  one  I  am  thinking  of." 

"  Then  it  must  be  the  tiger,"  said  John. 

"  No,"  replied 'Lawrence,  shaking  his  head. 

"  Then  it  must  be  the  whale,"  said  John.     "  Whales  de- 


OXYGEN.  19 

vour  an  enormous  quantity  of  little  fishes,  and  squids,  and 
such  things.  They  strain  them  out  of  the  water  when  they 
spout.  I  read  it  in  a  book."  '•' 

"  No,"  replied  Lawrence, "  it  is  not  the  whale." 

"  I  know  what  it  is,"  said  Flippy.     "  It  is  rats." 

Lawrence  laughed. 

"Why,  you  see,  the  reason  why  the  rats  devour  so 
much,"  said  Flippy,  looking  very  serious, "  is  because  there 
are  so  many  of  them.  There  are  more  rats  in  the  world 
than  any  thing  else." 

Lawrence  said  that  Flippy  had  made  a  very  good  guess, 
for  rats  really  were  great  devourers,  and  there  were  so 
many  of  them  in  the  world,  as  Flippy  said,  that  the  amount 
that  was  eaten  up  by  the  whole  race  was  enormous.  But 
the  devourer  that  he  was  thinking  of  beat  the  rats  entirely. 
It  consumed  more  than  all  the  lions,  tigers,  whales,  and 
rats  a  hundred  times  over.  It  was  oxygen. 

"  What's  that  ?"  asked  Flippy. 

"  It  is  something  in  the  air,"  said  Lawrence. 

"Yes,"  said  John.    "I  know  about  that.     It  is  gas." 

"  It  is  gas  while  it  is  in  the  air,"  replied  Lawrence, "  but 
when  it  has  devoured  any  thing  it  often  becomes  liquid  or 
solid,  in  union  with  what  it  has  devoured.  There  is  more 
of  it  in  the  world  than  there  is  of  any  thing  else.  It  forms 
about  one  quarter  of  the  substance  of  the  air,  about  one 
half  of  nearly  all  the  rocks  and  earth,  and  nearly  nine 
tenths  of  all  the  water  in  the  rivers  and  in  the  sea.  So 
you  see,  Flippy,  that  there  is  a  greater  amount  of  oxygen 
in  the  world  than  even  of  rats. 

"But  then,"  continued  Lawrence, "it  is  only  that  portion 
of  the  oxygen  which  is  in  the  air  that  acts  as  a  devourer. 
All  that  is  in  the  rocks  and  in  the  ground,  and  also  all 
that  which  forms  a  part  of  the  water  of  the  rivers  and  of 
the  sea,  has  got  its  fill  with  what  it  has  already  devoured, 


20  THE    GREAT    DEVOURER. 

and  wants  no  more.  What  is  in  the  air  is  free  and  hungry. 
It  is  all  the  time  on  the  watch  for  something  to  devour." 

Here  Flippy  began  to  look  a  little  weary.  John,  who 
had  read  and  studied  somewhat  on  these  subjects,  was 
quite  interested  in  what  Lawrence  was  saying,  simply  be- 
cause he  knew  something  about  it  already.  He  had  read 
about  oxygen,  and  had  heard  some  lectures  about  it,  and 
had  seen  the  lecturer'  prepare  some  of  it ;  that  is,  separate 
a  portion  of  it  from  certain  substances  with  which  it  was 
combined,  so  as  to  obtain  some  jars  of  it  pure,  and  then 
burn  phosphorus,  and  charcoal,  and  sulphur,  and  other 
combustibles  in  it,  thus  producing  a  very  intense  ignition 
and  a  very  brilliant  light.  But  he  had  never  before  heard 
how  vast  a  portion  of  what  exists  in  this  world,  whether 
air,  or  water,  or  land,  consists  of  this  substance,  and  still 
less  had  he  ever  heard  that  the  land  and  sea  are  formed  of 
substances  with  which  oxygen  is  already  combined,  and 
that  it  lies  quiet  in  them  in  consequence  of  being  satisfied 
with  the  combination;  while  that  which  is  in  the  air  is 
free,  and  is  all  the  time  on  the  watch  for  something  which 
it  too  could  devour. 

So  John  was  very  much  interested  in  what  Lawrence 
said.  But  Flippy,  knowing  nothing  about  oxygen  at  all, 
was  not  interested,  and  soon  went  away.  If  it  had  been 
about  the  devourings  of  lions,  tigers,  or  rats,  he  too  would 
have  been  interested,  and  would  have  remained,  for  he 
knew  something  about  such  devourers  as  those. 

And  this  is  an  illustration  of  one  of  the  great  advantages 
of  learning.  When  you  know  a  little  about  any  thing,  that 
knowledge  adds  greatly  to  the  pleasure  and  interest  you 
take  in  learning  more.  If  a  man  were  to  deliver  a  lecture 
on  fishing  to  a  company  of  boys,  those  would  be  most  in- 
terested in  the  lecture  who  knew  most  about  fishing  be- 
fore. If  the  lecture  were  upon  electricity,  those  would  like 


VALUE    OF    KNOWLEDGE.  21 

it  best  who  had  had  electric  machines  themselves,  and  had 
learned  something  of  the  science  by  their  own  experiments. 
So  a  great  many  more  people  in  this  country  are  interested 
•in  reading  books  of  travels  in  England  than  in  France,  be- 
cause they  know  more  about  England  than  about  France ; 
and  more  are  interested  in  reading  about  France  than 
about  India,  because  they  know  more  about  France  than 
about  India. 

This  is  a  great  encouragement  to  us  all  to  acquire  knowl- 
edge by  every  means  in  our  power,  for  we  not  only  have 
the  pleasure  of  knowing  what  we  learn  at  the  time,  but  we 
lay  up  for  ourselves  a  future  reward  by  adding  to  the  zest, 
that  is,  the  intensity,  of  the  pleasure  we  shall  derive  from 
the  additional  knowledge  on  the  same  subject  which  we 
may  acquire  at  any  future  time. 


22  LIFE,  DEATH,  AND    DISSOLUTION. 


CHAPTER  II. 

LIFE,  DEATH,  AND   DISSOLUTION. 

"  WE  boys  prepared  some  oxygen  ourselves  once,"  said 
John.  "  We  learned  how  to  do  it  at  the  lecture,  at  school." 

"  How  did  you  do  it  ?"  asked  Lawrence. 

"  Why,  we  put  the  materials  in  a  bottle,"  said  John, 
"  and  put  a  pipe-stem  through  the  cork,  and  then  fitted  an 
India-rubber  tube  to  the  top  of  the  pipe-stem,  and  carried 
the  end  of  the  tube  under  a  glass  jar,  which  we  held  upside 
down  in  the  water  in  a  water-pail.  Pretty  soon  the  oxy- 
gen gas  began  to  come  over  through  the  pipe  and  the 
tube,  and  bubbled  up  in  the  jar,  until  all  the  water  in  the 
jar  was  driven  out,  and  it  was  filled  with  oxygen  instead. 
Then  we  slid  a  plate  under  the  mouth  of  the  jar,  and  turned 
it  right  side  up,  and  set  it  on  the  table.  Only  we  kept  the 
plate  on  it,  to  prevent  the  oxygen  from  coming  out.  You 
see  the  jar  was  full  of  oxygen  gas,  but  it  did  not  look  like 
any  thing  at  all.  It  looked  just  as  if  the  jar  was  empty, 
or,  at  least,  as  if  there  was  nothing  in  it  but  air."* 

"  How  do  you  know  there  was  any  thing  in  it  but  air  ?"- 
asked  Lawrence. 

"  Oh,  we  burned  some  things  in  it,"  replied  John,  "  and 

*  The  opposite  cut  illustrates  an  apparatus  for  producing  oxygen.  It 
consists  of  a  stand,  with  rests  to  support  a  spirit-lamp  and  a  glass  retort ; 
a  tank  for  holding  water,  and  jars  for  collecting  oxygen.  Into  the  retort, 
which  holds  a  pint,  are  placed  three  ounces  of  chlorate  of  potassia  and  an 
ounce  of  peroxide  of  manganese ;  the  beak  of  the  retort  is  placed  under 
water  in  the  tank,  just  below  the  mouth  of  an  inverted  jar,  which  rests  on 
a  shelf.  The  lamp  is  then  lighted,  and  the  oxygen,  disengaged,  rises 
through  the  water  into  the  jar. 


PREPARING    OXYGEN. 


23 


they  burned  a  great  deal  brighter  than  they  would  in  the 
air." 

"  The  oxygen  devoured  them  very  eagerly,"  said  Law- 
rence. 

"Only  we  broke  our  jar,"  said  John.  "We  had  a  little, 
bit  of  phosphorus  that  the  professor  gave  us.  We  kept  it 
in  a  little  phial  in  water — for  it  will  take  fire  and  burn 
of  itself  if  it  comes  to  the  air." 

"  Yes,"  replied  Lawrence ;  "  oxygen  has  a  tremendously 
voracious  appetite  for  phosphorus.  It  will  seize  upon  it 
furiously  wherever  it  can  get  at  it.  The  only  means  of 
keeping  it  out  of  the  oxygen's  way  is  to  keep  it  under 
water." 

"  Yes,  but  there  is  one  thing  that  I  don't  understand," 
said  John.  "  Water  itself  is  about  nine  tenths  oxygen." 

"  It  is  nearer  eight  ninths,"  said  Lawrence. 

"  You  said  nine  tenths,  I  thought,"  rejoined  John.  "Nine 
tenths  of  the  water,  one  quarter  of  the  air,  and  one  half  the 
rocks  and  the  ground." 

"  I  am  glad  you  remember  so  well,"  said  Lawrence.    "  I 


PRODUCING   OXYGEN. 


24  LIFE,   DEATH,   AND    DISSOLUTION. 

said  about  nine  tenths,  as  I  only  meant  to  give  you  a  gen- 
eral idea  how  large  a  proportion  of  water  is  composed  of 
oxygen.  It  is  really  about  eight  ninths.  That  is,  there 
are  eight  parts  of  oxygen  to  one  of  hydrogen." 
.  "Well,  no  matter  about  the  exact  proportion,"  said 
John.  "  At  any  rate,  there  is  a  great  deal.  In  fact,  water 
is  nearly  all  oxygen.  Now,  if  oxygen  is  so  voracious  after 
phosphorus,  how  can  it  be  kept  under  water  any  better 
than  in  the  air?  Why  doesn't  the  oxygen  that  is  in  the 
water  attack  it  and  devour  it  ?" 

"  Because  the  oxygen  that  is  in  the  water,"  replied  Law- 
rence, "  has  its  appetite  satisfied  by  the  hydrogen  which  it 
has  already  devoured;  while  that  which  is  in  the  air  is 
free,  or,  at  least,  comparatively  free,  and  so  is  still  hungry." 

"  Or,  in  other  words,"  continued  Lawrence, "  to  give  up 
representing  the  oxygen  as  a  wild  beast,  and  to  talk  plain 
English  about  it,  the  oxygen  in  water  is  already  combined 
with  hydrogen,  for  which  it  has  a  prodigiously  strong  af- 
finity, and  all  its  force  is  expended  and  neutralized.  It  will 
not  leave  the  hydrogen  for  the  sake  of  the  phosphorus. 
Whereas  in  the  air,  the  substance  which  it  is  united  with 
is  nitrogen,  and  it  is  either  not  combined  with  the  nitrogen 
at  all,  but  only  mixed  with  it,  and  so  each  particle  is  in  full 
and  free  possession  of  all  its  native  force — or,  if  it  is  chem- 
ically combined  with  it,  it  is  held  so  weakly  that  it  is  al- 
ways ready  to  leave  it  and  seize  upon  the  phosphorus,  for 
which  it  has  a  very  much  stronger  affinity." 

"  Yes,"  said  John, "  I  see.  Well,  at  any  rate,  the  phos- 
phorus remained  quiet  as  long  as  we  kept  it  under  water ; 
but  when  we  took  it  out,  and  let  it  down  into  the  oxygen 
in  a  kind  of  spoon  that  we  made  out  of  a  strip  of  tin,  and 
then  set  it  on  fire  with  a  wire  that  we  heated  hot  at  one 
end  and  reached  down  to  it,  it  blazed  out  tremendously, 
and  made  such  a  bright  light  that  it  dazzled  us  to  look  at 


THE  ABUNDANCE  OF  OXYGEN.  25 

it,  till  it  was  hid  by  the  white  smoke ;  and  by-and-by  some 
drops  fell  down  into  the  bottom  of  the  jar  and  broke  it, 
and  all  the  white  smoke  came  out  into  the  room.  As  soon 
as  the  jar  cracked,  the  boys  all  ran  off  toward  the  door. 
They  thought  they  were  going  to  be  blown  up." 

Here  John  laughed  at  the  recollection  of  the  panic  which 
was  occasioned  among  the  boys  at  the  close  of  their  ex- 
periment. 

"  Then  you  know  something  about  oxygen,  it  seems," 
said  Lawrence — "  at  least  about  its  nature  and  action  on  a 
small  scale." 

"Yes,"  replied  John;  "but  I  did  not  know  any  thing 
about  there  being  such  enormous  quantities  of  it  in  the 
world." 

Lawrence  was  perfectly  correct  in  his  statements.  The 
quantity  of  oxygen  in  the  world  is  really  enormous,  form- 
ing, as  it  would  seem,  more  than  one  half  of  all  that  por- 
tion of  the  material  world  which  comes  under  our  observa- 
tion. How  far  this  abundance  of  oxygen  may  extend  into 
the  interior  of  the  earth  we  do  not  know.  But  in  the  at- 
mosphere, in  the  water  of  the  sea  and  of  the  rivers,  and  in 
all  that  portion  of  the  solid  substance  of  the  earth  which 
lies  near  enough  to  the  surface  to  be  examined  by  man, 
oxygen  forms  the  principal  constituent. 

Of  this,  however,  it  is  only  that  which  is  in  the  air  that 
is  free.  All  that  is  in  the  water,  and  in  the  earth,  has  its 
prodigious  chemical  affinity,  or  its  "  voracious  appetite," 
as  Lawrence  called  it,  satisfied  with  the  substances  with 
which  it  is  already  combined ;  and  there  are  very  few  sub- 
stances for  which  it  will  quit  those  which  it  already  thus 
holds  to  enter  into  any  new  combinations.  That  which  is 
in  the  air,  however,  is  free,  or  at  least  comparatively  free, 
and  is  ready  to  attack  and  devour  any  thing  that  comes 
within  its  reach. 

B 


26  LIFE,  DEATH,   AND    DISSOLUTION. 

When  I  say  all  that  is  in  the  water,  I  mean  all  that  is  in 
the  combination  which  forms  the  substance  of  the  water 
itself.  There  is  usually  a  quantity  of  common  air  mingled 
with  water,  and  this  air  contains  its  proper  proportion  of 
oxygen,  which  is  free  to  act  upon  other  substances,  when 
they  are  wet  with  the  water,  just  like  the  oxygen  in  any 
other  air. 

Oxygen  that  is  free  has  two  ways  of  devouring  sub- 
stances that  come  within  its  reach.  One  is  quiet  and  slow, 
and  the  other  excessively  rapid  and  violent.  At  the  or- 
dinary temperature  of  the  atmosphere,  that  is,  when  the 
substances  which  it  is  to  act  upon  are  moderately  cool,  it 
consumes  them  slowly  and  quietly.  It  eats  into  iron  in 
this  way,  forming  rust ;  for  iron  rust  is  a  combination  of 
oxygen  and  iron,  or,  as  the  chemists  call  it,  an  oxide  of 
^ron.  It  gradually  consumes  the  leaves  and  dead  wood 
that  fall  in  the  forest,  producing  what  is  called  vegetable 
decay.  It  devours  in  the  same  way,  or  helps  to  devour, 
every  dead  animal  body,  and  carries  off  in  gases,  into  the 
air,  or  into  solutions  into  the  ground,  the  substances  which 
compose  it.  In  these,  which  are  its  quiet  ways  of  acting, 
it  is  incessantly  occupied  all  over  the  earth — consuming 
slowly  and  silently  all  the  animal  and  vegetable  substances 
which  are  produced  on  the  globe,  attacking  each  one  as 
soon  as  death  puts  the  substances  of  which  they  are  com- 
posed into  its  power.  Some  of  the  new  combinations 
which  it  thus  makes  float  away  into  the  air,  and  some  are 
carried  by  rains  into  the  ground. 

And  what  is  very  curious,  and  also  fundamentally  im- 
portant to  one  who  wishes  to  understand  the  grand  opera- 
tions of  nature,  the  processes  of  vegetation  consist  in  the 
main  of  the  recovery  of  these  substances  from  their  combi- 
nations with  oxygen,  through  the  agency  of  the  heat  and 
chemical  power  of  the  suny  and  in  reconstituting  them  in 


VEGETABLE    GROWTH   AND   DECAY.  27 

the  forms  of  vegetable  and  animal  life.  They  continue  in 
these  forms,  protected  in  some  mysterious  way  by  the  vital 
principle,  until  death  comes  to  set  them  free  again,  and  to 
put  them  within  the  reach  and  at  the  disposal  of  oxygen 
once  more. 

The  two  principal  substances  which  the  sun  employs  in 
the  construction  of  the  tissues  of  plants,  and  which  it  has 
to  recover,  by  its  chemical  force,  from  the  possession  of 
oxygen,  are  carbon  and  hydrogen.  These  are  the  chief 
constituents  of  vegetable  and  animal  substances.  The  ox- 
ygen holds  the  hydrogen  in  water,  and  the  carbon  in  a 
portion  of  the  air  called  carbonic  acid  gas.  But  in  some 
mysterious  way,  not  at  all  well  understood,  the  sun,  by  the 
exercise  of  a  prodigious  chemical  force,  working  in  the 
leaves  of  plants,  separates  these  elements  from  their  com- 
binations, and  sends  the  oxygen  off,  empty  and  hungry, 
back  into  the  air,  while  the  carbon  and  hydrogen  are  con- 
veyed away  through  the  vessels  of  the  plant,  and  formed 
into  wood,  bark,  leaves,  flowers,  and  fruit.  The  oxygen 
can  not  touch  them  again  so  long  as  life  remains.  When 
these  substances  are  transferred  to  the  bodies  of  animals 
— as  the  leaves  of  grass,  for  instance,  eaten  by  oxen  or 
sheep — or  fruits  or  grain  by  man,  the  animal  life  protects 
them.  But  when  they  are  no  longer  thus  protected, 
whether  by  being  rejected  from  the  system  or  by  the 
death  of  the  animal,  then  the  turn  of  oxygen  comes  again, 
and  they  are  carried  off  by  it  into  the  two  grand  store- 
houses of  nature,  the  soil  which  covers  the  surface  of  the 
ground,  and  the  air. 

Of  course  a  statement  made  in  this  simple  form  gives 
only  a  very  general  idea  of  the  leading  aspect  of  the  phe- 
nomena. The  variations  and  exceptions  from  this  general 
statement,  and  the  endless  multiplicity  of  detail  which  re- 
sult from  the  action  and  interaction  of  all  the  forces  in- 


28  LIFE,  DEATH,  AND   DISSOLUTION. 

volved,  make  the  whole  operation  so  intricate  that  the  hu- 
man mind  can  never  hope  to  unravel  all  its  complications. 
It  will  be  of  advantage,  however,  to  the  young  student  to 
keep  in  mind  the  general  idea  here  expressed  as  tending  to 
give  system  to  his  thoughts,  and  enabling  him  the  better 
to  understand  and  appreciate  the  individual  facts  which 
may  from  time  to  time  come  under  his  knowledge. 

The  principles  stated  summarily  are  these : 

1st.  That  oxygen  is  the  most  abundant  substance  in  all 
that  portion  of  the  natural  world  accessible  to  us,  and  the 
great  agent  by  means  of  which  all  the  principal  operations 
of  nature  on  the  surface  of  the  earth  are  performed. 

2d.  That  the  active  portion  of  this  oxygen  is  mainly  that 
which  exists  in  a  feeble  union  with  nitrogen  in  the  air; 
that  which  exists  in  the  earth  and  in  the  water  being  con- 
fined in  fixed  combinations,  and  thus  reduced  to  a  condi- 
tion of  inertness  and  repose. 

3d.  That  the  great  processes  of  animal  and  vegetable 
life  consist  generally,  and  in  the  main,  though  with  an  in- 
finite number  of  variations  and  exceptions  in  detail,  in  sep- 
arating certain  substances,  the  chief  of  which  are  hydrogen 
and  carbon,  from  their  combinations  with  oxygen,  by  the 
superior  force  of  the  chemical  action  of  the  sun  acting  in 
the  leaves  of  plants,  and  in  combining  them  in  new  forms, 
namely,  those  of  vegetable  and  animal  tissues.  That  they 
are  protected  in  these  new  combinations  in  some  myste- 
rious way  by  the  principle  of  life;  but  that  when  this  fails, 
oxygen  again  resumes  its  power  over  them,  and  bears 
them  away  into  the  earth  or  into  the  air,  and  holds  them 
till  they  are  once  more  taken  in  by  the  roots  or  leaves  of 
plants,  and  impressed  again  in  the  service  of  life.  And  so 
the  work  goes  on  in  an  eternal  round. 

The  material  substances  which  form  the  human  body  are 
subject  to  the  same  law.  When  the  body,  after  death,  is 


THE    INTENTION    OF    NATURE.  31 

allowed  to  take  the  course  which  nature  intended,  the  ele- 
ments which  compose  it  being  no  longer  of  use  in  the  serv- 
ice of  life  in  one  form,  are  immediately  prepared  to  enter 
it  in  another.  They  soon  become  beautifully  transformed, 
and  appear  again  in  the  flowers  of  the  garden,  the  foliage 
of  the  forest,  the  verdure  of  the  meadows  and  fields,  or  in 
some  other  form  of  the  universal  bloom  with  which  vegeta- 
tion embellishes  the  world.  Man,  it  seems,  however,  often 
does  all  he  can  to  prevent  this  transformation.  By  his 
tombs,  his  sarcophagi,  his  caskets,  and  his  chemical  em- 
balmings, he  strives  to  hold  back  the  substance  of  the  life- 
less body  from  this  natural  and  charming  destination,  and, 
by  stopping  it  in  its  transition,  to  retain  it  forever  in  a  con- 
dition of  ghastly  and  revolting  decay.  In  doing  this  he  is 
striving  to  thwart  the  intentions  of  nature,  which  it  would 
seem,  in  such  a  case,  he  ought  to  regard  as  the  will  of  God. 
But  to  return.  In  accordance  with  what  has  been  ex- 
plained, if  we  were  to  go  into  a  forest  some  day  in  mid- 
summer, and  had  eyes  delicate  enough  to  see  what  was 
going  on  there,  we  should  perceive  in  all  the  leaves  of  the 
trees  the  incessant  movement  of  a  vast  force,  brought  by 
the  rays  of  the  sun,  and  employed  in  separating  the  hydro- 
gen and  carbon  from  their  combinations  with  oxygen  in 
carbonic  acid  gas  and  in  water,  and  sending  the  oxygen 
off  free ;  and,  on  the  other  hand,  on  the  ground,  and  in  the 
lungs  and  spiracles  of  every  insect,  beast,  and  bird,  an 
equally  active  movement,  in  which  the  oxygen  is  engaged 
in  recovering  possession  of  the  material  of  which  it  had 
before  been  despoiled,  and  re-forming  carbonic  acid  and 
water  again,  to  furnish  the  future  processes  of  life  with 
fresh  supplies.  In  a  tropical  forest  these  processes  go  on 
with  redoubled  energy,  on  account  of  the  extraordinary 
force  of  the  solar  radiations,  which  are  always  vertical,  or 
nearly  vertical  there. 


32  LIFE,   DEATH,  AND    DISSOLUTION. 

It  thus  appears  that,  since  the  element  of  oxygen  is 
every  where  and  always  at  work  over  the  whole  surface 
of  the  globe,  and  that  it  is  the  fate  of  every  living  thing  to 
be  sooner  or  later  devoured  by  it,  and  that  even  all  that 
the  lions,  and  tigers,  and  vultures,  and  rats  devour  in  the 
first  instance  they  have  to  give  up,  as  well  as  to  surren- 
der the  substances  composing  their  own  bodies,  in  the 
end,  to  the  voracious  rapacity  of  this  omnipresent  element, 
Lawrence  was  perfectly  justified  in  designating  it  as  the 
Great  Devourer. 

We  must  not,  however,  fall  into  the  mistake  of  suppos- 
ing that  by  the  great  devourer  is  meant  fire.  It  is  not  fire, 
but  oxygen.  Fire  is  only  an  effect  which  oxygen  produces 
in  one  of  its  many  modes  of  seizing  its  prey ;  and  the  sub- 
stances in  which  fire  is  produced  by  its  mode  of  consuming 
them  form  an  infinitely  small  part  of  the  whole  amount 
which  it  devours.  By  far  the  largest  portion,  indeed  al- 
most the  whole,  is  consumed  by  a  kind  of  action  which, 
though  universal,  all-pervading,  and  irresistible,  is  silent, 
gentle,  and  for  the  most  part  entirely  unobserved. 

But  it  is  time  to  bring  this  lecture  to  an  end,  and  to  pro- 
ceed with  the  account  of  the  embarkation  of  the  party  of 
travelers  on  board  the  Scotia. 


FUNCTIONS    OF    OXYGEN.  33 


CHAPTER  m. 

GOING    ON    BOARD. 

JOHN  had  been  so  much  interested  in  what  Lawrence  had 
explained  to  him  about  the  great  function  of  oxygen  in  re- 
lation to  the  vast  processes  of  vegetable  and  animal  life, 
and  in  rendering  possible  their  perpetual  renovation,  that 
he  forgot  the  question  about  the  comparative  combustibil- 
ity of  wood  and  iron. 

And  here,  perhaps,  I  ought  to  remark,  that  although,  in 
view  of  the  rapacious  appetite,  so  to  speak,  of  the  element 
oxygen,  and  the  enormous  quantities  of  the  other  elements 
which  it  continually  consumes,  it  is  natural  enough,  still, 
perhaps,  it  is  hardly  fair,  to  stigmatize  it  as  simply  a  de- 
vourer.  Its  great  function  being,  as  we  have  seen,  to  re- 
ceive the  materials  which  have  been  employed  by  the  prin- 
ciple of  life,  and,  after  having  fulfilled  their  purpose,  have 
been  abandoned,  and  to  convey  them  away,  and  keep  them 
in  its  custody  in  the  two  great  storehouses  of  nature,  the 
soil  and  the  air,  until  they  are  again  required,  it  might,  per- 
haps, as  justly  be  designated  as  the  great  receiver  and  cus- 
todian of  nature's  stores,  ready  to  deliver  them  at  any  time 
on  demand  by  the  sun,  as  to  be  called  a  devourer ;  and  to 
consider  it  as  serving  and  co-operating  with  the  sun  in  sus- 
taining and  carrying  forward  the  vast  cycle  of  birth,  life, 
death,  and  dissolution  in  its  eternal  round,  rather  than  as 
acting  the  part  of  an  antagonist  and  enemy.  The  facts, 
however,  are  all  clear,  and  in  their  general  aspect  easily  to 
be  understood ;  and  they  have  a  very  grand  significance 
to  those  qualified  properly  to  appreciate  them,  under  what- 
B  2 


34  GOING    ON    BOARD. 

ever  figurative  disguises  our  fancy  may  amuse  itself  in 
representing  them. 

About  an  hour  after  breakfast,  while  Lawrence  and  John 
were  setting  in  one  of  the  small  parlors,  each  with  a  light 
coat  over  his  arm,  and  a  small  valise  in  his  hand,  an  at- 
tendant of  the  hotel  came  in  and  told  them  that  their  car- 
riage was  ready. 

So  they  went  down  the  broad  staircase,  and  through  the 
wide  open  hall — which  was  crowded  with  people  coming 
and  going,  and  encumbered  with  vast  piles  of  trunks  and 
other  baggage — until  they  came  to  the  great  entrance 
door,  where  a  scene  of  extraordinary  noise  and  confusion 
opened  before  them.  The  street  was  full  of  omnibuses, 
cars,  carriages,  and  trucks,  that  were  making  their  way  as 
well  as  they  could  around  and  among  each  other,  with 
thundering  din.  A  long  row  of  coaches  and  cabs  were 
drawn  up  along  the  edge  of  the  sidewalk  in  front  of  the 
hotel,  and  great  crowds  of  foot-passengers  were  going  and 
coming  on  the  broad  flag-stone  walks — clerks  and  men  of 
business  hurrying  along,  eager  to  reach  their  counting- 
rooms  before  bank-hours — elegantly  dressed  ladies,  walking 
in  pairs — groups  of  school-boys  and  school-girls,  with  little 
packages  of  books  fastened  together  by  a  leather  strap  in 
their  hands,  and  nurses  taking  children  out  to  walk,  or 
propelling  babies  in  pretty  perambulators.  John,  not  hav- 
ing been  much  in  the  city,  was  much  impressed  with  this 
scene. 

Directly  before  the  door  was  a  carriage,  and  John,  on 
looking  up  to  the  driver's  seat,  saw  that  Flippy  was  sitting 
there  by  the  side  of  the  driver. 

The  waiter  who  had  notified  Lawrence  and  John  that 
their  carriage  was  ready,  advanced  and  opened  the  door 
of  this  carriage  as  if  for  them  to  get  in. 


INEFFICIENCY    OF    GOVERNMENT.  35 

"This  is  not  our  carriage,"  said  John.  "This  is  Flip- 
pyV 

"  I  thought  he  belonged  to  your  party,"  said  the  waiter. 

Just  at  this  moment  Lawrence  and  John  heard  a  lady's 
voice  saying, 

"  That  is  not  our  carnage.     Flippy,  come  down  !" 

"  Yes,  mother,"  said  Flippy.  "  He  says  he's  going  to  the 
Scotia." 

"  Who  says  so  ?"  asked  his  mother. 

"  The  driver,"  replied  Flippy. 

"  That's  nothing,"  said  the  lady.  "  He  is  going  with  an- 
other party.  Come  down !  Here's  our  carriage  out  here. 
Make  him  come  down,  Edmund." 

These  last  words  were  addressed  to  a  gentleman  who 
had  just  at  that  moment  appeared  at  the  "Lady's  En- 
trance" to  the  hotel,  where  the  lady  was  standing.  He 
had  his  hands  full  of  bags  and  parcels,  and  seemed  worried 
and  bewildered.  He  looked  first  at  the  carriages,  and  then 
up  at  Flippy,  and  then  at  his  wife,  and  did  not  appear  to 
know  what  to  do. 

At  length  he  seemed  to  comprehend  the  situation,  and 
called  out  imperiously, 

"  Flippy,  come  down  from  there  this  instant !  That  is 
not  our  carriage !  Here's  our  carriage  !" 

But  imperiousness  in  the  manner  of  giving  commands  is 
a  very  inefficient  substitute  for  established  authority  in 
enforcing  them.  The  most  stern  and  determined  tone  of 
voice  in  issuing  an  order  will  fall  powerless  unless  the  re- 
cipient of  it  has  been  trained  to  obey.  Flippy  did  not  move. 

"  Flippy,"  repeated  his  mother,  "  come  down  this  in- 
stant !" 

"  No,"  said  Flippy.  "  There  is  no  place  for  ine  to  ride 
outside  in  your  carriage,  and  I'm  going  in  this.  It  don't 
make  no  difference.  It's  going  to  the  same  place." 


36  GOING    OX    BOARD. 

"  But  the  gentleman  will  not  be  willing  to  have  you  go 
in  his  carriage,"  said  his  mother.  "  He  has  engaged  that 
carriage  for  himself.  Come  down  !" 

Here  Lawrence  turned  to  the  lady  and  said  that,  if  she 
had  no  objection,  her  son  could  go  in  his  carriage  perfectly 
well.  It  would  be  no  inconvenience  to  him. 

The  lady  looked  first  at  Lawrence,  then  at  Flippy,  then 
at  her  husband,  and  seemed  very  much  perplexed,  as  she 
exclaimed, "  What  a  vexation  !"  In  the  mean  time  the  hub- 
bub all  around  her  increased.  The  hotel  waiter  had  put 
two  enormous  trunks  upon  the  carriage  which  had  been 
engaged  for  her,  and  was  helping  her  husband  to  put  in 
the  bags  and  parcels.  Different  drivers  were  calling  upon 
each  other  to  "hurry  up,"  and  to  "move  on."  Finally, 
without  stopping  really  to  decide  the  question,  she  found 
herself  so  hemmed  in  by  the  necessities  of  the  case,  that 
she  allowed  herself  to  be  helped  into  the  carriage.  Her 
husband  stepped  in  after  her,  the  door  was  shut,  and  the 
waiter  called  out  to  the  driver, "  Jersey  City 7"  "Steamer 
Scotia  /"  and  the  carriage  moved  on. 

"  I  wish,  Mr.  Gray,"  said  the  lady,  as  the  carriage  moved 
away  from  the  door, "  that  you  would  teach  Flippy  to  obey 
a  little  better.  You  have  no  authority  over  him  at  all." 

"My  dear,"  said  Mr.  Gray,  with  a  gesture  of  impatience, 
"  what  can  I  do  ?  I  ordered  him  positively  to  come  down. 
What  more  could  I  do  ?" 

"  We  don't  know  any  thing  about  those  people  that  he 
has  gone  with,"  continued  Mrs.  Gray,  without  taking  any 
notice  of  her  husband's  reply.  "  It  is  very  annoying  !" 

"  I  dare  say  they  are  very  respectable  people,"  said  Mr. 
Gray.  "  I  did  not  see  any  thing  out  of  the  way.  But 
that's  no  excuse  for  Flippy." 

In  the  mean  time  the  carriage  of  Lawrence  and  John  had 
begun  to  move  too. 


A  PROPOSITION.  37 

"  Good !"  exclaimed  John,  in  a  tone  of  great  satisfaction. 
"We're  off!  But,  Lawrence,  you  should  not  have  encour- 
aged this  boy  in  disobeying  his  mother  by  telling  him  that 
you  would  let  him  go  with  us." 

"I  did  not  tell  him  that  I  would  let  him  go  with  us,"  re- 
plied Lawrence.  "  I  told  his  mother  that  she  might  let  him 
go  with  us,  if  she  chose." 

"That  comes  to  the  same  thing,"  said  John. 

"  Yes,"  replied  Lawrence,  "  it  comes  to  the  same  thing 
in  the  end ;  but  there  may  easily  be  two  ways  leading  to 
the  same  end,  and  yet  one  of  them  be  right  and  the  other 
wrong." 

"  I  think  you  encouraged  him  in  his  disobedience,"  said 
John. 

"  Do  you  ?"  said  Lawrence.  "  Then  you  must  fine  me  for 
a  misdemeanor." 

"  Fine  you,"  repeated  John. 

"  Yes,"  replied  Lawrence.  "  I  will  make  a  bargain  with 
you,  if  you  will  agree  to  it,  that  every  time  either  of  us 
commits  a  misdemeanor  he  is  to  be  fined  five  cents ;  and 
every  time  he  is  guilty  of  a  less  offense  than  a  misde- 
meanor, such  as  we  might  call  &  peccadillo,  he  shall  be  fined 
two  cents.  You  shall  be  treasurer  and  shall  keep  the 
money,  and  when  we  get  to  Paris  we  will  spend  it  in  a  ride 
out  into  the  environs  of  Paris." 

John  readily  agreed  to  this,  but,  after  having  agreed  to 
it,  he  asked  what  the  difference  was  between  a  misde- 
meanor and  a  peccadillo.  Lawrence  replied  that  there  was 
not,  in  fact,  any  well-defined  difference,  except  that  a  pecca- 
dillo was  a  very  light  offense,  and  a  misdemeanor  was 
something  more  serious. 

"We  can  understand,  if  you  please,"  said  Lawrence,  "that 
misdemeanor  means  something  that  is  morally  wrong — 
that  is  to  say,  something  wrong  in  respect  to  the  feelings 


38  GOING    ON   BOARD. 

and  intent  of  the  heart — such  as  disobedience  in  ourselves, 
or  the  encouraging  of  disobedience  in  others ;  while  a  pec- 
cadillo is  something  that  affects  mere  outward  action." 

"  Such  as  what  ?"  asked  John. 

"  Such  as  drumming  with  your  knife  on  your  plate  from 
thoughtlessness,"  said  Lawrence,  "  while  waiting  for  your 
dinner  to  come." 

John  laughed  and  said  he  should  not  do  that.  But  Law- 
rence said  he  might  do  things  like  that,  that  is,  things  that 
showed  no  evil  intention,  but  were  only  acts  of  thought- 
lessness, which  were  disagreeable  to  other  people.  John 
said  if  he  did  he  was  willing  to  pay  two  cents  for  each  one, 
on  jcondition  that  Lawrence  would  do  the  same. 

So  it  was  agreed  that  for  every  misdemeanor  the  guilty 
one  was  to  pay  five  cents,  and  for  every  peccadillo  two 
cents,  into  a  common  treasury,  and  that  the  money  so  col- 
lected should  be  spent  in  an  excursion  when  they  reached 
Paris. 

Lawrence  exercised  a  little  innocent  artifice  in  making 
this  arrangement  with  John.  He  adopted  it  as  an  easy 
and  good-natured  method  of  maintaining  that  slight  degree 
of  supervision  and  control  which  is  usually  necessary,  or, 
at  least,  often  desirable,  in  such  cases,  on  the  part  of  the 
older  over  the  younger  of  two  young  people  making  a 
journey  together.  He  had  no  expectation  of  actually  fining 
John  for  any  shortcomings  that  he  might  observe,  for  John 
was  a  considerate  and  careful  boy,  and  he  was  convinced 
that  it  would  be  very  seldom  that  he  would  do  any  thing 
requiring  interposition  on  his  part.  And  then,  moreover, 
he  supposed  that  when  accused,  he  would  defend  himself, 
and  that  in  the  end  the  fine  would  not  be  imposed.  On 
the  other  hand,  he  had  no  doubt  that  John  would  watch 
him  very  closely,  and  often  charge  him  with  misdemeanors 
or  peccadilloes ;  and  that  in  such  cases,  after  a  little  feeble 


CROSSING    THE    FERRY.  39 

defense  of  himself,  he  should  always  yield,  so  that  it  would 
be  he  himself  who  would  have  all  the  fines  to  pay.  He 
thought,  however,  that  the  incidental  conversations  which 
would  arise  in  discussing  and  settling  the  questions  would 
be  the  means  of  making  John  very  careful  about  his  de- 
meanor, and  enable  him,  that  is,  Lawrence,  to  check  him 
when  he  was  wrong,  and  thus  to  exercise  a  proper  author- 
ity over  him  in  a  manner  which,  though  in  a  sense  playful, 
would  still  be  effectual,  without  tending  at  all  to  irritate 
or  vex  the  boy,  as  open  fault-finding  would  have  done. 

In  the  mean  time  the  carriage  went  on,  threading  its  way 
among  the  carts  and  omnibuses,  through  various  streets, 
drawing  gradually  nearer  to  the  river,  as  John  perceived 
by  glimpses  of  the  water  which  now  and  then  came  into 
view.  At  length  it  stopped.  It  had  been  stopped  several 
times  before  by  "jams"  of  vehicles,  but  there  seemed  to  be 
no  jam  here. 

"  It  is  the  ferry,"  said  Lawrence. 

"  Is  there  a  ferry  to  cross  ?"  asked  John. 

"Yes,"  replied  Lawrence,  "we  go  across  the  North 
River.  The  Cunard  wharf  is  in  Jersey  City.  We  call  it 
sailing  from  New  York,  but  it  is  really  from  New  Jersey." 

Presently  a  heavy  jingling  sound  was  heard,  occasioned 
by  the  running  of  the  great  iron  chain  by  which  the  ferry- 
boat was  drawn  up  and  secured  to  the  landing-bridge,  and 
immediately  a  great  gate  was  opened,  and  a  long  train  of 
ponderous  vehicles  began  to  come  out,  and,  as  soon  as  they 
had  passed,  the  train  that  had  been  waiting  began  to  go  in. 
The  boat  was  large  enough  to  contain  two  long  lines  of 
these  carts  and  carriages,  with  saloons  for  passengers  on 
each  side.  Lawrence  and  John  remained  in  the  carriage, 
but  John  looked  out  at  the  window  and  called  to  Flippy. 

"  Flippy,"  said  he ;  "  hallo  !" 

"  Come  up  here,"  said  Flippy  in  reply.     "  Come  up  here, 


40  GOING    ON    BOARD. 

and  see  haw  this  ferry-boat  is  jammed  full  of  wagons  and 
teams." 

"  I  can't  get  up  there,"  said  John. 

"  Yes,"  said  Flippy, "  you  can  climb  up  out  of  the  win- 
dow." 

"  Would  you  ?"  said  John,  looking  back  at  Lawrence. 

".^should  gain  by  it,  at  any  rate,"  said  Lawrence. 

"  How  so  ?"  asked  John. 

"I  could  fine  you  for  a  peccadillo." 

"  Would  that  be  a  peccadillo  ?"  asked  John. 

"  Yes,"  said  Lawrence ;  "  climbing  out  of  the  window  of 
a  carriage  to  get  to  the  driver's  seat  with  another  boy, 
in  crossing  the  Jersey  City  Ferry,  to  embark  for  Europe, 
would  be  a  first-class  peccadillo.  I  don't  think  two  cents 
would  be  fine  enough  for  it.  But  I  suppose  I  should  have 
to  be  contented  with  two  cents,  since  that  was  the  law  we 
made.  Of  course  we  must  go  according  to  law." 

"  But  you  might  call  it  a  misdemeanor,"  said  John, "  and 
so  make  the  fine  five  cents." 

"No,"  replied  Lawrence,  "it  would  not  be  a  misde- 
meanor on  our  system,  because  there  would  be  no  moral 
considerations  involved.  Unless,  indeed,  I  forbade  your 
going,  and  you  should  disobey ;  then  it  would  be  a  misde- 
meanor." 

"  John,"  said  Flippy,  calling  out  from  his  seat  in  front, 
"  are  you  coming  ?" 

"No,"  said  John. 

Soon  after  this  a  little  bell  was  heard,  and  the  motion  of 
the  boat  was  immediately  felt  to  be  checked.  A  moment 
following  there  was  a  little  bump,  and  then  a  jingling 
sound,  caused  by  the  running  out  of  the  great  chain  by 
which  the  boat  was  to  be  drawn  up  snug  to  the  land- 
ing-bridge. The  long  trains  of  carriages  and  wagons 
then  moved  on  out  of  the  boat,  and  the  one  which  con- 


A   SEA-GOING    STEAMER.  43 

tained  our  travelers  took  the  direction  toward  the  Cunard 
dock. 

Arriving  at  the  dock,  the  carriage  entered,  through  a 
great  gate,  into  a  spacious  inclosure,  with  piers,  and  steam- 
ers, and  masts,  and  vast  iron  chimneys  painted  red,  and 
carts,  and  carriages,  and  piles  of  boxes,  and  heaps  of  trunks 
and  other  baggage,  and  groups  of  sailors  pulling  in  concert 
upon  ropes,  and  other  such  nautical  sights  and  sounds, 
combining  to  form  a  very  busy  and  noisy  scene.  The  car- 
riage went  on  under  a  long  shed,  passing  by  several  other 
steamers,  until  it  reached  the  Scotia,  and  then  stopped. 
Lawrence  and  John  got  out,  Flippy  at  the  same  time 
climbing  down  from  his  high  seat  over  the  forward  wheel. 
They  took  their  bags  and  parcels  in  their  hands. 

"  Let  me  have  one,"  said  Flippy. 

One  of  the  hands  from  the  steamer  came  and  took  from 
them  the  heaviest  of  their  packages,  and  then  they  all  went 
up  the  gangway  plank  on  board.  The  gangway  plank,  as 
they  called  it,  was  a  broad  and  well-constructed  bridge, 
with  a  good  substantial  railing  on  each  side,  so  that  there 
was  no  danger  of  falling  into  the  water  in  going  on  board. 

John,  who  had  never  been  on  board  of  any  but  river  and 
Sound  steamers  before,  was  quite  impressed  with  the  solid 
and  massive  character  of  every  thing  that  he  saw  around 
him  as  he  entered  the  ship.  The  bulwarks  which  bordered 
the  main  deck  were  seven  or  eight  feet  high,  and  seemed 
to  him  to  be  a  foot  thick,  and  very  solid.  The  main  saloon, 
with  its  long  row  of  windows — the  flights  of  steps  seen 
here  and  there — the  paddle-boxes — the  monstrous  frames 
supporting  the  various  timbers  on  the  deck,  some  appar- 
ently connected  with  the  machinery,  and  others  serving 
purposes  which  he  could  not  understand — the  long  and 
slender,  but  very  solid-looking  bridge,  running  across  from 
the  top  of  one  of  the  paddle-boxes  to  the  other,  which 


44  GOING    ON    BOARD. 

served  for  a  walk  and  look-out  for  the  captain  and  pilot — 
and,  more  than  all  the  rest,  a  view  of  the  immense  engines, 
which  were  to  be  seen  in  looking  down  through  very  large 
square  openings  in  the  decks,  guarded  by  massive  railings 
so  high  that  Flippy  had  to  stand  on  tiptoe  to  look  over — 
these  and  many  other  such  things  combined  to  impress 
both  Lawrence  and  John  very  strongly  with  the  dignity 
and  grandeur  of  an  ocean  steamer. 

They  only  took  a  glance  at  these  things  in  passing,  and 
then  went  down  below  to  find  their  state-room  and  deposit 
their  bags  and  parcels.  Flippy  remained  on  the  upper 
deck  to  watch  for  the  carriage  of  his  father  and  mother. 
Lawrence  and  John  went  through  a  passage-way  which 
opened  on  the  main  deck  between  the  dining  saloon  and 
what  seemed  to  be  an  immense  china  closet,  then  descend- 
ed a  winding  staircase  with  steps  covered  with  plates  of 
metal,  then  passed  through  a  long  passage-way  with  doors 
opening  into  the  various  state-rooms  on  each  side.  They 
began  to  look  about  for  the  numbers  denoting  their  room, 
when  a  pleasant-looking  woman  met  them  and  directed 
them.  They  found  their  room  at  the  end  of  a  short  and 
narrow  passage  which  led  between  two  inner  state-rooms. 
Theirs  was  an  outer  one — that  is,  next  the  side  of  the  ship. 
When  they  entered  it,  John  found  that,  though  called  a 
state-room,  it  was  really  rather  a  closet  than  a  room.  On 
one  side,  which  was,  of  course,  the  side  next  the  sea,  there 
was  a  small  round  window  quite  high  up.  It  was  fitted 
with  one  very  thick  pane  of  glass,  which  was  set  in  a  very 
solid  and  heavy  brass  frame.  This  frame  had  a  hinge  on 
one  side,  and  very  strong  screws  on  the  other  side,  which, 
by  means  of  a  stout  handle,  could  be  screwed  tight  into  a 
socket  on  the  side  opposite  to  the  hinge,  so  as  to  fasten 
the  window  securely  in  heavy  weather.  The  window  was 
open  when  John  went  into  the  room,  and  the  first  thing  he 


THE    STATE-KOOM.  45 

did  was  to  climb  up  upon  a  very  narrow  cushioned  seat 
under  it,  and  look  out.  But  there  was  very  little  to  be 
seen. 

On  the  other  side  of  the  cabin  were  two  berths — that 
is,  narrow  beds  made  on  shelves  against  the  wall,  one 
above  the  other ;  and  at  the  end  opposite  the  door  was  a 
fixed  wash-stand,  with  pitcher  and  basin  set  in  a  marble 
top,  and  a  cupboard  below.  Above  it  was  a  shelf  with  a 
decanter  and  two  tumblers  upon  it,  set  in  holes  to  prevent 
their  sliding  off  the  shelf  in  a  heavy  sea ;  and  there  were 
two  looking-glasses,  and  two  or  three  massive  hooks  to 
hang  clothes  up  on,  and  two  great  round  life-preservers, 
and  various  other  conveniences. 

John  looked  at  all  these  things  one  after  the  other,  and 
then  said, 

"  It  is  little  enough — the  place ;  but  I  don't  see  but  that 
they  have  put  every  thing  in  it  that  we  want." 

"  Yes,"  replied  Lawrence ;  "  and  things  that  I  hope  we 
shall  not  want — the  life-preservers." 

These  life-preservers  were  great  round  rings,  and  John 
found,  by  rapping  upon  one  of  them,  that  they  were  hol- 
low. They  were  of  such  a  size  that  a  man  could  put  them 
over  his  head  and  shoulders,  and  then  draw  his  arms  up 
through  them,  and  so  float  in  the  water,  supported  by  the 
buoyancy  of  the  life-preserver  under  his  arms. 

"  Yes,"  said  John,  "  I  hope  we  shall  not  have  to  use  them 
on  this  voyage,  but  I  should  like  very  much  to  have  one 
of  them  to  play  with  when  I  go  in  swimming  in  the  river 
at  home." 

Lawrence  and  John  stowed  their  parcels  and  bags  under 
the  lower  berth  and  under  the  seat,  and  then  Lawrence 
asked  John  which  berth  he  would  have  for  his,  the  upper 
or  the  under  one. 

"  The  upper  one,"  said  John. 


46 


GOING    ON   BOARD. 


"  You'll  have  a  hard  climb  to  get  up  to  it,"  said  Law- 
rence. 

"  That's  the  reason  I  like  it,"  said  John.  "  I  like  to  climb ; 
and,  besides,  it  is  easy  enough  to  climb  up  into  that  berth." 

So  saying,  John  stepped  upon  the  seat  beyond  where  his 


THE   STATE-ROOM. 


USES    OF   A  WINDOW.  47 

cousin  was  sitting,  and  thence  upon  the  wash-stand,  and 
from  the  wash-stand  he  clambered  into  the  upper  berth, 
and,  crouching  down  in  it  on  his  hands  and  knees,  he  be- 
gan to  look  out  through  the  little  round  window,  while 
Lawrence,  making  a  desk  of  his  little  valise,  which  he  held 
in  his  lap,  began  to  write  a  farewell  note  to  somebody  or 
other. 

"  See !"  said  John ;  "  I  can  look  out  at  the  window  all  the 
way." 

"  There  won't  be  much  to  see,"  said  Lawrence,  "  when 
we  are  out  in  mid-ocean." 

"  I  may  see  a  ship,"  said  John. 

"  We  meet  very  few  ships  on  the  open  sea,"  said  Law- 
rence. 

"  I  may  see  an  iceberg,"  said  John. 

"  I  hope  we  shall  not  meet  any  icebergs  at  all,"  replied 
Lawrence. 

"  I  may  see  a  whale,"  said  John. 

"True,"  replied  Lawrence,  "you  may  possibly  see  a 
whale." 

"  At  any  rate,"  said  John, "  I  like  the  upper  berth  the 
best." 

So  it  was  all  arranged,  and  Lawrence  and  John  soon  aft- 
erward left  their  cabin  and  went  up  on  deck  to  see  what 
had  become  of  Flippy. 


48  LEAVING   POET. 


CHAPTER  IV. 

LEAVING    POET. 

ON  the  evening  of  the  first  day  of  the  voyage,  when  the 
steamer,  having  taken  all  her  passengers  on  board,  had 
sailed  down  the  harbor,  and  had  dismissed  the  pilot,  and 
was  now  proceeding,  in  reality,  very  swiftly,  though  ap- 
parently very  slowly,  out  to  sea,  John  and  Flippy  were  sit- 
ting together  on  the  deck  watching  the  land,  that  was  now 
so  distant  as  to  look  like  a  long,  low  line  of  cloud  near  the 
horizon.  The  sea  was  smooth  and  the  air  was  calm.  But 
the  rapid  motion  of  the  ship  produced  something  like  a 
breeze  over  the  deck,  which  was,  moreover,  so  cool  as  to 
make  it  quite  agreeable  to  find  some  shelter  from  it. 
There  were,  however,  plenty  of  sheltered  places  furnished 
by  the  immense  paddle-boxes  and  smoke-pipes,  and  by  the 
fixtures  around  the  hatchway,  and  around  various  other 
openings  through  the  decks.  All  these  places  were  filled 
with  groups  of  ladies,  sitting  upon  camp-stools  and  fold- 
ing-chairs, enjoying  the  evening  air  and  the  smooth  sea, 
and  congratulating  each  other  on  their  being  favored  with 
so  charming  a  commencement  of  their  voyage.  Some  of 
the  ladies  were  talking  with  each  other  cheerily,  and 
seemed  quite  light-hearted  and  gay.  Others  were  silent, 
thoughtful,  and  sad.  This  was  very  natural,  for  among 
them  there  were,  on  the  one  hand,  many  whose  hearts  were 
entirely  at  ease,  as,  for  example,  brides  setting  out,  full  of 
gladness  and  hope,  on  their  wedding-tour,  and  young  la- 
dies on  their  way  to  Paris,  with  bright  anticipations  of  the 
joys  and  gayeties  that  awaited  them  there,  and  European 


•THE    PASSENGERS.  49" 

mothers  returning  gladly  to  their  homes  and  families  in 
the  Old  World,  after  having  accompanied  their  husbands 
on  a  business  tour  to  the  New ;  while,  on  the  other  hand, 
there  was  here  an  American  mother  leaving  young  chil- 
dren at  home  to  accompany  a  husband  in  failing  health 
on  a  foreign  tour,  equally  anxious  about  the  sick  one  taken 
with  her  and  the  helpless  ones  left  behind,  and  there  a 
youthful  couple  in  mourning  for  an  only  child,  who,  after 
vainly  contending  with  their  grief  for  half  a  year  in  their 
own  desolate  home,  were  now  going  to  attempt  to  aid 
themselves  in  diverting  their  minds  a  little  from  their 
overwhelming  sorrow  by  the  scenes  and  excitements  of 
a  foreign  tour,  and  were  already  half  sorry  that  they  came. 

As  for  the  brides,  however,  perhaps  I  have  placed  them 
in  the  wrong  class,  in  the  above  enumeration,  in  represent- 
ing them  as  leaving  their  native  land  with  hearts  filled 
with  gladness  and  joy.  The  gladness  and  joy,  in  the  case 
of  such  a  bride,  are  mingled  with  sadness  and  fear.  She 
can  not  help  feeling  that  she  has  sundered  forever  the  tie 
which  has  bound  her  to  all  that  have  ever  been  most  dear 
to  her,  and  committed  herself  irrevocably  to  a  new  bond, 
her  faith  in  which,  though  she  feels  sure  that  it  is  implicit, 
complete,  and  unwavering,  is,  after  all,  not  wholly  unmixed 
with  those  half-misgivings  which  we  always  feel  in  intrust- 
ing ourselves  to  what  is  new  and  utterly  untried. 

Besides  these  various  groups,  who  were  seated  in  differ- 
ent nooks  and  corners,  upon  camp-stools,  folding  chairs,  and 
cushioned  settees,  there  were  groups  of  children  running 
to  and  fro,  delighted  with  the  new  acquaintances  which 
they  were  making  among  each  other,  and  with  the  novelty 
and  strangeness  of  the  scenes  into  which  they  had  been  so 
suddenly  brought ;  for  the  transition  from  the  tumult  and 
noise  of  the  hotels  and  crowded  streets  of  New  York  to 
the  quiet  scenes,  and  to  the  steady  and  gentle  motion  of 

C 


50  LEAVING   POET.       * 

the  ship,  gliding  over  smooth  water,  far  out  at  sea,  now 
that  it  was  over,  seemed  to  them  like  a  dream. 

John  and  Flippy  were  standing  together,  just  before 
eight  o'clock,  looking  down  through  an  opening  in  the 
deck,  and  through  the  machinery  below,  to  a  place  far,  far 
down  in  the  hold,  where  they  could  see  the  forms  of  half- 
naked  men  shoveling  coal  into  the  mouths  of  furnaces 
glowing  with  furious  heat,  when  Lawrence  came  to  them 
and  asked  them  to  go  down  with  him  into  the  saloon. 

"  They  are  going  to  perform  a  very  curious  chemical  ex- 
periment there,"  said  he,  "  and  I  want  you  to  see  it.  At 
least  I  would  like  to  have  you  go,  John,"  said  he.  "  Flip- 
py can  do  as  he  likes.  I  am  sure  you  will  be  interested 
in  it.  As  to  Flippy,  I  don't  know." 

"  What  experiment  is  it  ?"  asked  John. 

"It  is  the  fusion  and  combustion  of  a  hydrocarbon," 
said  Lawrence,  gravely. 

"  What  does  it  do  ?"  asked  Flippy. 

"  It  does  not  do  any  thing  except  make  a  bright  light," 
said  Lawrence. 

"  I  should  like  to  see  it,  if  it  does  that,"  said  Flippy, "  and 
I'll  go." 

So  they  all  went  down  into  the  saloon  together. 

The  saloon  was  a  long  room  elegantly  decorated,  and 
brilliant  with  mirrors  and  plate-glass.  It  was  furnished 
with  a  long  row  of  tables  on  each  side,  a  broad  passage- 
way being  left  open  between  them  in  the  middle.  There 
was  a  range  of  handsomely  and  comfortably  cushioned 
benches  on  each  side  of  the  tables — one,  of  course,  back 
against  the  walls,  and  the  other  on  the  side  of  the  passage- 
way. Lawrence  and  John  had  been  in  this  room  some 
times  before  during  the  day.  Indeed,  they  had  taken  din- 
ner here,  and  now  the  tables  were  set  for  tea. 

Lawrence  led  the  way  between  two  of  the  tables,  and 


THE    EXPERIMENT.  53 

took  a  seat  upon  a  cushioned  bench,  or  sofa,  as  it  might, 
perhaps,  be  called,  that  extended  along  the  wall.  The  two 
boys  followed  him  and  took  seats  by  the  side  of  him.  The 
tables  were  all  set  for  tea,  and  conspicuous  among  the 
other  things  that  were  placed  upon  them  were  two  long 
rows  of  tall  candles  in  silvered  candlesticks,  which  extend- 
ed along  the  whole  length  of  the  room. 

"  Who  is  going  to  perform  the  experiment?"  asked  John. 

"  One  of  the  waiters,"  replied  Lawrence. 

John  was  rather  surprised  at  this,  and,  looking  up  at 
Lawrence,  he  thought  he  observed  something  like  a  supx 
pressed  smile  lurking  in  the  expression  of  his  countenance. 

"  Now,  Lawrence,"  he  exclaimed, "  you  have  been  mak- 
ing fools  of  us  !  I'm  sure  you  have ;  and  if  you  have — " 

"  No,"  replied  Lawrence,  "  you'll  find  that  it  will  turn 
out  just  as  I  said.  I  said  they  were  going  to  perform  a 
very  curious  chemical  experiment,  and  there  the  waiter 
comes  to  do  it  now." 

As  he  said  this  he  pointed  toward  the  door,  where  a 
steward — they  always  call  the  waiters  at  sea  stewards  and 
stewardesses — was  coming  in  with  a  lighted  candle  in  his 
hand,  with  which  to  light  the  other  candles. 

"  He  is  going  to  light  the  candles,"  said  Lawrence, "  and 
the  burning  of  a  candle  is  truly  a  very  curious  chemical 
process." 

"You  said  it  was  something  extraordinary,"  rejoined 
John, "  and  there  is  nothing  extraordinary  at  all  in  lighting 
a  candle.  You  made  fools  of  us,  and  I  think  it  was  a  pec- 
cadillo or  a  misdemeanor.  I  think  it  was  a  full  misdemean- 
or, and  that  you  ought  to  be  fined  five  cents.  Oughtn't 
he,  Flippy  ?  He  brought  us  down  here  to  show  us  some- 
thing extraordinary,  and  it  is  nothing  but  lighting  the 
candles,  which  is  one  of  the  most  common  things  in  the 
world." 


54  LEAVING   POET. 

" Curious"  rejoined  Lawrence.  " I  think  I  said  curious, 
and  I'll  leave  it  to  Flippy  if  it  is  not  so.  I  will  explain  to 
him  and  to  you  all  about  the  burning  of  a  candle,  and  if  he 
does  not  decide  that  it  is  curious,  I  will  admit  that  I  made 
fools  of  you,  and  that  it  was  a  peccadillo,  and  so  I  will  pay 
the  fine." 

"  A  misdemeanor,"  said  John ;  "  it  was  a  full  misde- 
meanor." 

"  Very  well,"  rejoined  Lawrence, "  a  misdemeanor.  I  will 
agree  to  pay  the  fine  for  a  misdemeanor — five  cents,  if 
Flippy  so  decides.  But  they  are  coming  in  to  tea  now,  so 
we  will  wait  till  after  tea." 


INSTRUCTION    WELL   TIMED.  55 


CHAPTER  V. 

COMBUSTION. 

THE  people  came  in  very  irregularly  for  tea,  and  the 
boys  proposed  that  they  should  go  up  on  deck  a  little 
while  to  see  what  was  going  on,  and  so  return  afterward 
and  hear  what  Lawrence  had  to  say  about  the  burning  of 
candles.  Lawrence  said  that  was  just  what  he  should  like, 
and  so  the  boys  went  away.  He  remained  in  his  seat  and 
began  to  read. 

The  reason  why  he  was  glad  to  have  the  boys  go  up  on 
deck  for  a  while  was  that  he  wished  to  have  their  curiosity 
satisfied  in  respect  to  the  visible  scenes  and  images  which 
presented  themselves  to  view  on  board  the  ship,  before  he 
attempted  to  lead  their  thoughts  to  the  more  hidden  mys- 
teries of  chemical  action.  In  other  words,  he  did  not  wish 
that,  while  he  was  explaining  to  them  what  was  curious  in 
the  burning  of  a  candle,  their  minds  should  be  interested 
in  something  else.  A  great  deal  of  excellent  advice  and 
instruction  offered  by  older  persons  to  younger  is  lost,  in 
respect  to  its  effect,  simply  by  being  ill-timed — that  is,  by 
being  offered  at  times  when  the  minds  of  the  listeners  are 
preoccupied  with  other  thoughts  or  other  desires. 

It  was  half  past  eight  o'clock  when  the  boys  came  down. 

"  Did  we  stay  too  long  ?"  asked  John. 

"  Not  at  all  too  long,"  said  Lawrence.  "  The  longer  you 
can  find  something  to  amuse  you  on  deck  the  better." 

"  It's  getting  cold  up  there  now,"  said  John,  "  and  so  we 
have  come  down  to  hear  about  the  candle." 

So  the  boys  sat  down,  one  on  each  side  of  Lawrence, 


56  COMBUSTION. 

upon  the  seat  along  the  wall,  back  of  the  table,  and  Law- 
rence began  as  follows : 

"  You  remember  what  I  told  you,  John,  about  the  sun's 
working  all  day  in  separating  carbon  and  hydrogen  from 
the  oxygen  in  water  and  air,  and  delivering  these  ele- 
ments to  the  control  of  the  principle  of  life  in  the  plant ; 
and  that  they  remained  under  the  control  of  this  principle 
while  they  continued  parts  of  a  living  being,  whether  plant 
or  animal,  and  that  at  length,  when  they  were  thrown  off, 
or  when  the  plant  or  animal  dies,  the  oxygen  that  is  free 
in  the  atmosphere,  and  in  the  air  contained  in  water,  at- 
tacks them,  and  recombines  with  them  slowly,  and  holds 
them  strongly  until  the  sun  takes  them  away  from  it  again 
in  the  leaves  of  new  plants?" 

John  said  that  he  remembered  about  this,  but  that  Flip- 
py was  not  there  when  he  explained  it,  and  that  perhaps 
he  had  better  explain  it  to  Flippy  again. 

"  No,"  said  Flippy,  "  I  don't  care  about  it  much.  All  I 
want  to  hear  about  is  the  candle,  so  as  to  see  if  Mr.  Law- 
rence is  to  pay  the  fine." 

"  Then,"  said  Lawrence, "  I  will  begin  at  once  about  the 
candle ;  though  first  I  must  say  that  the  chief  elements 
that  the  sun  takes  away  from  the  oxygen  in  the  leaves  are 
hydrogen  and  carbon,  and  these  are  the  two  substances 
that  are  chiefly  used  in  making  all  vegetable  and  animal 
substances. 

"  You  can  understand  and  remember  that,  Flippy,  at  any 
rate,"  added  Lawrence,  turning  to  Flippy, "  namely,  that 
all  vegetable  and  animal  substances  that  will  burn  when 
they  are  dry  are  composed  chiefly  of  hydrogen  and  carbon, 
and  so  they  are  called  hydrocarbons.  Hydrogen  burns 
alone  with  a  faint  bluish  flame,  that  gives  very  little  light. 
Carbon  burns  without  any  flame,  but  becomes  of  a  very 
bright  red  heat.  When  they  burn  together,  the  hydrogen 


HYDROCARBONS.  5V 

forms  the  gaseous  portion  of  the  flame,  while  the  incan- 
descent particles  of  the  carbon  that  are  in  it — that  is,  the 
particles  of  carbon  that  have  become  red  hot  or  white  hot, 
give  it  its  body  and  brightness." 

The  boys  looked  at  the  flame  of  the  candle  to  see  wheth- 
er they  could  detect  the  incandescent  particles  of  the  car- 
bon in  it. 

"  There  are  a  great  many  different  hydrocarbons,"  said 
Lawrence.  "  Wood  is  substantially  a  hydrocarbon,  though 
the  term  is  more  generally  applied  to  such  substances  as 
resin,  wax,  tallow,  and  oils,  which  consist  almost  exclusive- 
ly of  hydrogen  and  carbon,  while  wood  and  other  such 
vegetable  and  animal  tissues  contain  a  considerable  por- 
tion of  other  substances.  Anthracite  coal  is  a  carbon 
simply,  for  it  does  not  contain  any  hydrogen,  and  so  will 
not  burn  with  flame ;  and  bones,  and  shells,  and  other  such 
substances  are  not  hydrocarbons  at  all,  as  is  shown  by  the 
fact  that  they  can  not  be  set  on  fire  in  any  way." 

Lawrence  then  proceeded  to  name  a  great  variety  of 
substances,  and  to  ask  the  boys  whether  they  were  hydro- 
carbons or  not.  Even  Flippy  soon  began  to  be  quite  in- 
terested in  answering  these  questions ;  for,  just  as  it  is 
always  a  pleasure  to  a  boy  to  exercise  his  limbs  and  exter- 
nal organs  in  new  ways  that  are  pointed  out  to  him,  pro- 
vided the  things  proposed  to  be  done  are  such  as  he  can 
do,  so  he  is  always  interested  in  the  mental  action  of  com- 
prehending any  ideal  distinction  which  is  explained  to  him 
— that  is,  a  distinction  which  he  does  not  see  in  the  objects 
themselves  actually  before  him,  but  which  he  has  to  con- 
ceive of  in  his  mind. 

I  knew  a  boy  once — a  little  fellow  who  had  not  yet 
learned  to  read — whose  brother  gave  him  an  excellent  les- 
son one  day  in  explaining  to  him  the  meaning  of  the  word 
quadruped,  and  then  naming  to  him  a  great  number  of  an- 

C2 


58  COMBUSTION. 

imals,  and  asking  of  each  one  whether  it  was  a  quadruped 
or  not.  He  called  it  a  lesson ;  and  a  very  useful  lesson  it 
was  for  the  child,  as  it  exercised,  and  so  helped  to  develop, 
his  thinking  powers.  And  so  interested  was  the  child  in 
the  lesson  that  he  asked  for  another.  So  his  brother  the 
next  day  explained  to  him  the  meaning  of  the  word  biped, 
and  then  named  to  him  again  all  the  various  animals  that 
he  had  named  the  day  before,  and  asked  him  if  they  were 
bipeds.  Of  course  the  answers  would  be  all  the  reverse 
of  those  which  he  had  given  before,  when  asked  if  they 
were  quadrupeds. 

If  you  try  this  experiment,  or  any  other  which  calls  into 
action,  not  too  severely,  the  thinking  powers  of  young  chil- 
dren, you  will  find  that  they  will  be  greatly  interested  in 
such  an  exercise  of  their  mental  faculties.  Only  you  must 
be  careful  not  to  make  the  work  too  difficult  for  them,  and 
you  must  be  careful  to  choose  your  time,  as  Lawrence  did, 
when  their  minds  are  not  preoccupied  with  other  things. 

It  was  on  this  principle  that  Flippy  became  interested 
in  being  able  to  distinguish  the  class  of  hydrocarbons  from 
all  other  substances.  Lawrence  talked  about  them  for 
some  time  in  a  cursory  manner — that  is,  without  attempt- 
ing to  impart  any  special  information,  in  order  to  let  the 
boys  become  perfectly  familiar  with  the  word,  and  with 
the  general  character  of  the  class  of  substances  to  which 
it  was  applied. 

Carbon  and  hydrogen  are  both  combustible,  but  they 
burn  in  very  different  ways,  and  produce  very  different  re- 
sults. Lawrence,  in  order  to  interest  Flippy  in  such  sub- 
jects, and  thus  to  open  to  his  mind  hew  sources  of  instruc- 
tion, directed  a  considerable  portion  of  the  conversation 
particularly  to  him,  for  John  was  greatly  interested  in  such 
subjects  already.  This  was  simply  because  he  knew  many 
things  about  them  already,  while  Flippy  had  no  knowledge 


WHAT. IS   BURNING?  59 

of  them  at  all.  For,  as  I  have  said  before,  people  are  gen- 
erally more  interested  in  learning  more  about  that  of  which 
they  already  know  something,  than  in  beginning  to  learn 
about  something  of  which,  as  yet,  they  know  nothing  ^,t  jail. 

There  is,  indeed,  something  very  curious  about  the  burn- 
ing of  carbon  and  hydrogen,  but,  in  order  that  the  reader 
may  understand  it  clearly,  it  is  necessary  that  I  should  first 
explain  what  burning  actually  is.  Oxygen  has  two  ways 
of  seizing  and  combining  with  those  substances  for  which 
it  has  a  strong  affinity.  One  is  the  slow  and  gentle  way 
which  it  takes  with  these  substances  at  ordinary  tempera- 
tures, as,  for  example,  when  it  combines  with  iron  to  form 
rust,  or  when  it  combines  with  animal  and  vegetable  sub- 
stances, which  are  no  longer  protected  by  a  principle  of 
life,  in  the  processes  of  animal  and.  vegetable  decay.  These 
combinations  take  place  at  ordinary  temperatures.  If  the 
substances  are  too  cold,  as  when,  for  instance,  in  the  case 
of  animal  and  vegetable  substances,  they  are  frozen,  then 
it  can  not  take  place  at  all. 

This  is  the  philosophy  of  preserving  articles  of  food,  for 
example,  by  freezing  them,  or  packing  them  in  ice — that  is, 
by  this  treatment  they  and  the  oxygen  around  them  are 
kept  so  cool  that  they  can  not  combine — in  other  words, 
what  we  call  decay  can  not  go  on. 

If  now,  however,  we  increase  the  temperature  of  the  sub- 
stances gently,  as,  for  example,  taking  them  out  of  the  ice, 
and  exposing  them  to  the  warmth  of  a  common  summer 
day,  then  they  begin  slowly  to  combine.  The  wood,  if  it 
is  wood,  begins  to  decay,  which  decay  consists  essentially 
in  its  being  combined  with  oxygen,  and  the  new  combina- 
tion being  carried  off  intot  he  air.  This  is  so  slow  a  pro- 
cess, however,  that  a  heap  of  logs  lying  on  the  ground 
would  be  several  years,  ordinarily,  in  being  decomposed 
and  conveyed  away. 


60  COMBUSTION. 

If  now,  on  the  other  hand,  the  temperature  of  the  wood 
is  raised  to  a  great  heat — about  the  heat,  for  example,  of 
that  of  red-hot  iron — then,  for  some  mysterious  reason  or 
othe*  which  nobody  understands,  the  oxygen  begins  to 
seize  upon  the  carbon  or  hydrogen,  or  both,  of  which  the 
wood  is  composed,  with  the  utmost  avidity  and  violence. 
It  then  becomes  truly  a  devourer.  And  the  violence  of 
the  action  shows  itself  in  the  development  of  an  excessive 
degree  of  additional  heat.  This  is  what  we  call  burning. 
The  slow  and  gradual  consumption  of  a  substance  by  oxy- 
gen, without  the  development  of  great  heat,  we  do  not  call 
burning /  we  call  it  decay.  Sometimes  it  is  called  slow 
burning,  or  slow  combustion,  because  the  nature  of  the  two 
processes  seem  to  be  essentially  the  same,  except  in  the 
rapidity  with  which  they  take  place.  But  the  term  burn- 
ing, or,  rather,  combustion,  is  strictly  applied  only  to  those 
processes  of  the  combination  of  oxygen  with  carbon  or  hy- 
drogen which  are  so  rapid  and  violent  as  to  be  attended 
with  the  development  of  an  intense  degree  of  heat. 

I  say  burning  or  combustion,  as  if  these  two  terms  meant 
the  same  thing.  But  they  are  not,  by  any  means,  precisely 
synonymous.  Burning  is  the  term  used  in  common  par- 
lance, while  combustion  is  the  scientific  term ;  and,  as  is 
usually  the  case  in  respect  to  common  and  scientific  terms, 
the  former  is  more  loose  and  general  in  its  signification, 
being  applied  to  many  things  which  seem  alike  in  external 
appearance  and  in  their  effect  upon  the  senses,  though  they 
are,  or  may  be,  quite  different  in  their  essential  natures ; 
while  the  scientific  term  is  used  much  more  precisely,  and 
is  applied  only  to  a  certain  class  of  effects  which  are  of  pre- 
cisely the  same  nature. 

Thus  the  word  burning  is  applied  to  a  great  number  and 
variety  of  effects  produced  by  great  heat,  such  as  the  burn- 
ing of  lime,  in  which  the  action  of  oxygen,  so  far  as  the  lime 


WHAT   IS    DESTRUCTION?  61 

is  concerned,  has  nothing  to  do  ;  the  burning  of  a  boy's  fin- 
ger in  a  candle,  which  does  not  necessarily  imply  any  chem- 
ical change  at  all,  but  only  a  sensation  produced  in  the  nerv- 
ous system.  But  the  term  combustion  is  only  applied  to 
the  process  through  which  oxygen,  or  some  similar  sub- 
stance, produces  intense  heat  and  certain  destructive  ef- 
fects, through  the  extreme  violence  and  intensity  of  its  action. 
It  is  important,  however,  for  the  reader  to  understand 
that  by  destructive  effect  we  only  refer  to  the  particular 
combination  in  which  the  substances  existed,  and  not  to 
the  substances  themselves.  No  elements  can  be  destroyed, 
or  even  injured,  or  changed  in  any  degree,  either  in  quan- 
tity or  quality.  They  can  only  be  separated  from  their 
present  combinations,  and  set  free  to  form  new  ones.  Thus, 
when  a  boy  throws  a  letter  which  he  had  written  into  the 
fire,  and  it  is  burnt  up,  nothing  is  really  destroyed  but  the 
letter  as  a  letter.  The  carbon  and  hydrogen,  and  the 
other  substances  in  small  quantities  that  composed  the  pa- 
per, and  the  iron,  and  oxygen,  and  other  substances  in 
small  quantities  that  composed  the  ink,  would  not  be 
changed  at  all.  It  would  only  be  the  letter  as  a  letter — 
that  is,  the  particular  combination  of  these  substances  that 
would  be  destroyed.  The  carbon  and  hydrogen  would  go 
up  the  chimney  in  the  draft,  and  some  of  the  other  sub- 
stances would  remain,  to  fall  finally  into  the  ashes ;  but 
these  elements,  though  they  might  be  mixed  with  various 
other  substances  as  they  lay  upon  the  hearth,  or  floated 
away  into  the  air,  would  in  themselves  be,  in  their  own  es- 
sential nature,  entirely  unchanged — the  same  precisely  that 
they  were  before  they  went  into  combination  in  the  leaves 
of  the  cotton-tree,  out  of  which  the  tree  formed  the  cotton, 
of  which  the  spinner  and  weaver  formed  the  cloth,  of  which 
the  paper-maker  made  the  paper  on  which  the  boy  wrote 
the  letter, that  was  burned. 


62  COMBUSTION. 

The  term  combustion  is  thus  applied  to  the  process  by 
which  oxygen  seizes  upon  certain  other  elements  previous- 
ly existing  in  other  combinations,  and  forms  new  combi- 
nations, doing  this  with  such  violence  and  intensity  of 
action  as  to  develop  light  and  heat.  These  substances 
which  are  capable  of  being  thus  seized  and  devoured,  as  it 
were,  by  oxygen,  are  called  combustibles.  And  this  re- 
minds me  of  the  question  which  had  been  raised  between 
Lawrence  and  John,  whether  wood  or  iron  was  most  strict- 
ly and  completely  combustible,  which  question  they  had 
not  yet  settled,  and  which  they  seemed  to  have  forgotten. 
But  they  had  not  forgotten  it.  It  will  come  up  again  by- 
and-by. 


TRANSFORMATIONS.  63 


CHAPTER  VI. 

FLIPPY    A     REFEREE. 

LAWRENCE  explained  all  these  things  in  relation  to  the 
nature  of  combustion  to  Flippy  and  John.  John  listened 
to  it  all  with  great  attention,  and  even  Flippy  seemed  more 
interested  in  it  than  one  might  have  expected.  He  said 
at  last  that  he  thought  he  should  understand  it  better  if 
he  could  only  see  some  of  the  carbon  and  hydrogen,  so  as 
to  know  exactly  how  they  looked. 

Lawrence  replied  that  there  was  something  very  curious 
in  respect  to  the  question  of  seeing  those  substances, 
which  was  that  they,  like  all  other  elementary  substances, 
changed  their  form  and  appearance,  and  all  other  sensible 
qualities,  in  fact,  in  their  different  states  and  combinations, 
so  as  to  assume  every  possible  disguise. 

"  It  is  somewhat,"  he  said,  "  like  the  case  of  the  sub- 
stance of  the  slate-pencil,  wliich  is  black,  or  nearly  black, 
in  the  pencil  itself,  but  when  a  portion  of  it  is  rubbed  off 
upon  the  slate — as  happens  when  you  make  a  mark  with 
it — it  is  nearly  white.  In  the  same  manner,  iron,  when  it 
is  seen  by  itself  in  a  pure  and  solid  state,  as,  for  instance, 
when  you  look  at  the  end  of  a  bar  which  has  been  broken 
off,  is  of  a  bright  bluish  color ;  yet  when  it  is  combined 
with  a  certain  portion  of  oxygen  in  rust,  is  of  a  dull  brown, 
while  yet  the  oxygen  which  combined  with  the  iron  to 
form  the  rust,  as  it  existed  in  the  air  before  it  joined  the 
iron  to  form  the  rust,  had  no  brown  color,  and,  indeed,  no 
color  at  all,  but  was  perfectly  clear  and  transparent.  So 
the  substance  of  water,  when  it  is  in  the  form  of  water,  is 
liquid,  and  when  in  the  form  of  ice  it  is  solid  and  hard." 


64  FLIPPY    A    BEFEKEE. 

"  That's  because  it  is  frozen,"  said  Flippy. 

"  Yes,"  replied  Lawrence.  "  Calling  it  frozen  is  only  our 
way  of  saying  that  it  is  cold  and  hard,  but  in  substance  it 
is  only  water  still,  just  as  it  was  before.  When  water  be- 
comes of  a  certain  degree  of  coldness  it  becomes  hard,  and, 
on  the  other  hand,  when  it  is  heated  to  a  certain  extent,  it 
becomes  a  gas,  thin  and  completely  invisible,  and  lighter 
than  air.  We  call  it  then  steam;  but  it  is  water  still, 
though  it  has  changed  its  form  and  appearance." 

"But  we  can  see  steam,"  said  Flippy;  "it  looks  like 
white  smoke." 

"  Very  well,"  replied  Lawrence ;  "  but  even  in  that  case 
it  has  entirely  changed  its  form  and  appearance,  for  noth- 
ing can  be  more  unlike  in  appearance,  or  in  what  we  call 
sensible  qualities,  than  water  when  it  is  in  its  liquid  state, 
lying  quietly  and  heavily  in  a  bowl,  and  when  it  rises  into 
the  air  in  vapor  in  the  form  of  a  white  cloud.  Then,  when 
it  becomes  snow,  it  takes  the  form  of  a  white  powder." 

"  That's  very  queer,"  said  Flippy.  "  I  never  thought  of 
that  before." 

"  I  think  it  is  very  curious  indeed,"  said  Lawrence. 
. "  So  do  I,"  replied  Flippy. 

"These  changes  of  form  are  still  more  remarkable  in  the 
case  of  carbon,"  said  Lawrence. 

"I  thought  that  carbon  was  coal,"  said  Flippy. 

"It  is,"  replied  Lawrence,  "or,  rather,  some  kinds  of 
coal  are  composed  almost  entirely  of  carbon,  and  coal  is 
black.  But  we  can  not  say  on  that  account  that  carbon 
is  black,  for  these  candles  here  along  the  table  are  com- 
posed in  a  great  measure  of  carbon,  and  they  are  perfectly 
white." 

Here  Flippy  drew  one  of  the  candles  near  him,  and  ex- 
amined it  very  closely,  in  expectation  of  detecting  some 
very  minute  black  specks  in  it,  but  he  could  not. 


ACTION    OF    OXYGEN.  65 

"  If  I  had  a  microscope,"  said  he, "  perhaps  I  could  see 
them." 

"  No,"  replied  Lawrence. 

"  Not  if  it  magnified  a  thousand  times  ?"  asked  Flippy. 

"  No,"  replied  Lawrence,  "  not  if  it  magnified  a  thousand 
million  times.  You  could  not  see  any  thing  black  there, 
because  there  is  not  any  thing  black  there.  A  thing  is 
black  or  white,  not  according  to  the  nature  of  the  sub- 
stance that  composes  it,  but  according  to  the  manner  in 
which  the  particles  are  arranged  so  as  to  absorb  or  reflect 
the  light.  Now  in  the  candle  the  particles  of  carbon  in 
combination  with  those  of  hydrogen  are  arranged  so  as  to 
reflect  the  light  in  such  a  manner  as  to  look  white.  In 
coal  they  are  so  arranged  as  to  look  black.  In  the  dia- 
mond, which  is  composed  almost  entirely  of  carbon,  they 
are  arranged  so  as  to  allow  the  light  to  pass  entirely 
through,  and  thus  to  look  transparent." 

Lawrence  then  went  on  to  explain  the  structure  of  the 
candle,  and  the  nature  of  the  process  of  lighting  and  burn- 
ing it.  His  explanation  was  substantially  as  follows : 

The  hydrocarbon  of  which  the  candle  is  composed, 
whether  tallow,  or  paraifine,  or  spermaceti,  or  wax,  can 
only  be  combined  with  oxygen  in  an  exceedingly  slow  and 
gradual  manner,  so  long  as  it  remains  at  the  common  tem- 
perature of  the  air;  but  when  it  is  heated  to  a  certain 
point,  then  the  oxygen,  if  there  is  any  near,  seizes  upon  it 
with  the  greatest  avidity,  and  consumes  it  very  rapidly 
indeed,  and  with  so  much  violence  and  intensity  of  action 
as  to  produce  great  heat  and  bright  light.  No  one  knows 
at  all  why  the  oxygen  should  act  thus  so  much  more  pow- 
erful at  one  temperature  than  another,  or  why,  in  so  act- 
ing, it  should  give  out  so  much  additional  heat  and  light. 
We  know  something  about  the  quantity  of  heat  and  light 
that  is  thus  developed,  as  will  be  presently  explained,  but 


66  FLIPPY    A    REFEREE. 

very  little,  with  certainty,  about  the  manner  in  which  the 
action  of  the  oxygen  upon  the  hydrocarbon  develops  it. 

In  consequence  of  this  fact,  that  the  oxygen,  in  com- 
bining with  the  hydrogen  and  carbon,  develops  a  great 
amount  of  heat,  it  is  not  necessary  to  raise  the  whole  of 
the  substance  up  to  the  point  of  combustion  to  enable  the 
oxygen  to  consume  it  all.  It  is  only  necessary  to  heat  a 
small  portion  of  it,  for  the  heat  developed  by  the  combus- 
tion of  this  portion  will  raise  the  next  portion  of  it  up  to 
that  point,  and  that  the  next,  and  so  on  until  it  is  all  con- 
sumed. This  heating  of  a  small  part  of  any  hydrocarbon 
in  order  that  the  oxygen  may  begin  to  act  upon  it  visibly, 
and,  by  so  acting,  develop  heat  enough  to  bring  the  next 
portion  up  to  the  right  temperature,  so  that  it  can  seize 
upon  it  too,  is  what  we  do  when  we  light  a  lamp,  or  kindle 
a  fire.  We  set  the  oxygen  at  work  by  heating  up  a  part 
of  its  food  for  it. 

"  Cooking  it,  I  suppose,"  said  Flippy. 

"  Yes,"  said  Lawrence, "  you  might  call  it  that.  If  we 
cook  it  a  little,  just  so  that  the  oxygen  can  begin,  it  will  go 
on  cooking,  as  you  call  it,  the  rest  for  itself — each  portion 
in  succession,  as  fast  as  it  reaches  it." 

Lawrence  went  on  to  explain  that  this  was  the  way  the 
operation  proceeded  in  the  case  of  the  candle.  The  waiter 
brings  the  flame  of  another  candle  up  and  holds  it  against 
the  wick  a  moment.  This  heats  a  portion  of  the  wick  up 
to  the  point  that  enables  the  oxygen  in  the  air  to  combine 
with  it.  In  combining  with  it,  the  intensity  of  the  action 
is  so  great  that  the  next  portion  below  is  heated  up  to  the 
required  degree,  and  then  the  oxygen  combines  with  that 
and  develops  more  heat. 

ISTow,  if  the  wick  went  down  into  a  candle  of  stone,  or 
of  any  other  substance  which  was  already  combined  with 
oxygen,  then,  as  soon  as  the  projecting  part  was  burned,  it 


THE    CANDLE.  67 

would  go  out.  But  the  candle  is  formed  of  a  hydrocarbon, 
and  the  substance  of  it  has  a  strong  affinity  for  oxygen 
when  it  is  raised  to  a  proper  degree  of  heat.  But  the 
wick,  when  it  burns  down  to  it,  first  melts  a  portion  of  it, 
and  then  draws  it  up  into  the  fire  which  is  burning  in  the 
wick.  Here  it  is  heated  enough  to  enable  the  oxygen  to 
seize  it,  and,  in  seizing  it,  more  heat  is  developed  by  which 
more  of  the  wax,  or  spermaceti,  or  whatever  the  substance 
is  of  which  the  candle  is  composed,  is  drawn  up,  heated, 
and  burned.  Thus  the  process  is  really  a  very  curious 
one. 

As  Lawrence  explained  it  in  this  way  to  the  boys,  he 
told  them  that  by  looking  at  the  candle  very  ,, 

closely  they  could  see  the  current  of  melted  /^ 
material  flowing  constantly  up  into  the  wick, 
where,  of  course,  it  came  into  the  fire,  and  was 
heated  hot  enough  for  the  oxygen  of  the  sur- 
rounding air  to  combine  with  it,  and  by  so 
doing  develop  more  heat  for  melting  and  heat- 
ing the  next  portion. 

The  boys  looked  very  intently  into  the  can- 
dle to  watch  the  flow  of  the  melted  sperma- 
ceti as  it  passed  up  into  the  wick.  While  THE  OAlrDLE 
doing  so,  Flippy  observed  one  or  two  little  FLAME. 
dark-colored  motes  which  were  floating  in  the  melted  cur- 
rent, and  he  observed  that  they  went  up  first  till  they 
reached  the  edge  of  the  flame,  and  then  darted  back  again, 
as  if  they  were  burned ;  and  after  waiting  a  moment  near 
the  outer  edge  of  the  candle,  they  came  back  slowly,  till 
they  touched  the  fire,  when  they  darted  back  again  as 
before. 

"  Oh !  John,"  said  he, "  look  at  those  little  jiggers  that 
keep  swimming  back  and  forth.  They  go  up  to  the  fire 
till  it  burns  their  noses,  and  then  they  start  back  and  stay 


68  FLIPPY    A    REFEREE. 

away  a  little  while,  and  then  try  it  again.  See  !  What  are 
they,  and  what  makes  them  act  so  ?" 

Lawrence  said  that  he  could  tell  the  boys  what  they 
were  better  than  'he  could  tell  them  what  made  them  act 
so.  He  then  went  on  to  explain  that  the  cotton  of  the 
wick,  though  formed  chiefly  of  hydrogen  and  carbon,  which 
the  oxygen  could  consume,  contained  also  some  other  sub- 
stances which  came  from  the  earth,  and  which  the  oxygen 
had  previously  consumed — that  is,  with  which  it  was  al- 
ready combined,  and,  of  course,  it  could  not  combine  with 
them  again.  These  substances  remain  in  the  form  of  ashes, 
he  said,  when  wood,  or  paper,  or  cloth,  or  any  other  such 
substance  is  burned.  Even  in  so  small  a  thing  as  the  wick 
of  a  candle  there  is  a  certain  portion  which  can  not  be  con- 
sumed— that  is,  which  the  oxygen  can  not  combine  with, 
because  it  is  already  combined  with  all  the  oxygen  that  it 
can  take. 

This  incombustible  portion,  or  ash,  as  we  call  it,  in  the 
case  of  an  ordinary  fire,  remains  on  the  hearth  after  the  fire 
has  burned  out — that  is,  after  the  oxygen  has  combined 
with  all  the  hydrogen  and  carbon,  and  formed  gases  by 
combination  with  them,  which  have  gone  away  up  the 
chimney. 

In  the  case  of  the  wick  of  a  candle,  however,  especially 
in  candles  of  the  nicer  kinds,  the  particles  of  their  ashes 
are  so  delicate  and  minute  that  most  of  the  substance  of 
them  float  away  into  the  air  in  the  form  of  a  fine  dust,  or 
are  carried  up  in  the  current  of  hot  gases  which  are  pro- 
duced by  the  combustion  of  the  hydrogen  and  carbon. 

"These  little  motes  that  you  see,"  said  Lawrence,  in 
completing  his  explanation, "are  generally,!  suppose,  small 
portions  of  the  ashes  which  have  fallen  down  into  the  melt- 
ed spermaceti  or  wax,  though  they  may  sometimes  be  par- 
ticles of  dust  of  other  kinds  that  were  floating  about  in 


THE    QUESTION.  69 

the  atmosphere.  But  what  causes  them  to  play  back  and 
forth  in  that  way  is  a  puzzle.  I  can't  tell  you,  because  I 
don't  know." 

"  Can't  you  find  out  ?"  asked  Flippy. 

"  No,"  replied  Lawrence.  "  I  have  watched  them  very 
often,  but  never  could  understand  what  was  the  cause  of 
their  moving  in  that  manner  to  and  fro." 

"  I  mean  to  watch  them,"  said  Flippy, "  and  see  if  I  can't 
find  out." 

After  hearing  all  that  Lawrence  had  to  say  in  respect  to 
the  philosophy  of  combustion  as  exemplified  in  the  burn- 
ing of  a  candle,  John  admitted  that  it  was  very  curious, 
and  that  he  was  very  glad  to  have  it  explained  to  him,  but 
still  he  contended  that  Lawrence,  in  telling  them  that  the 
waiter  was  going  to  perform  a  chemical  experiment  in  the 
saloon,  had  made  fools  of  them,  and  that  he  ought  to  pay 
the  fine  for  a  misdemeanor. 

"  On  the  contrary,"  replied  Lawrence, "  it  seems  to  me 
that,  instead  of  making  fools  of  you,  I  have  made  you  wiser 
than  you  were  before,  by  explaining  all  this  philosophy  to 
you." 

"  That's  nothing,"  said  John.  "  You  deceived  us,  at  any 
rate ;  you  made  us  think  it  was  something  very  different 
from  lighting  a  candle.  Besides,  we  will  leave  it  to  Flippy 
to  decide." 

Lawrence  agreed  to  this,  and  so  the  case  was  stated  to 
Flippy,  and  the  arrangement  was  explained  to  him  by 
which  Lawrence  and  John  were  to  pay  into  a  common 
fund  a  fine  of  five  cents  for  every  misdemeanor,  and  two 
cents  for  every  peccadillo ;  and  they  explained  to  Flippy 
the  definition  which  they  had  agreed  to  give  to  these  two 
classes  of  offenses  respectively.  They  also  stated  to  him 
that  the  money  was  to  be  spent  in  an  excursion  in  the  en- 
virons of  Paris  when  they  should  reach  that  city. 


70  FLIPPY    A    REFEREE. 

"  But  that  won't  do  me  any  good,"  said  Flippy. 

"  Yes,"  replied  Lawrence, "  we  will  invite  you  to  go  with 
us  on  the  excursion,  if  you  like." 

"  Then,"  said  Flippy,  "I  decide  that  it  was  a  misdemean- 
or, and  he  must  pay  five  cents  fine.  You  see,"  he  added, 
by  way  of  justifying  his  judgment, "  that  we  must  get  all 
the  money  we  can  for  the  excursion,  so  as  to  have  a  good 
long  one." 

"  True,"  replied  Lawrence ;  "  but  do  you  think  it  was  any 
more  than  a  peccadillo — two  cents." 

"Yes,"  rejoined  Flippy, "it  was  a  misdemeanor — a  real 
misdemeanor." 

"Good!"  said  Lawrence.  "I'm  glad  to  have  such  a 
strict  judge.  He'll  be  more  likely  to  be  sharp  in  deciding 
against  you,  John,  when  it  comes  your  turn." 

"  But  I'm  not  going  to  have  any  turn,"  said  John.  "  I'm 
not  going  to  do  any  misdemeanors  or  peccadilloes  at  all." 

"  Oh  yes,"  said  Lawrence. 

"No,"  rejoined  John,  "I'm  determined  not  to  do  any 
thing  at  all." 

"  You  and  Flippy  will  get  to  fooling  together  on  the 
deck,"  rejoined  Lawrence,  "and  will  run  against,  or  disturb 
the  other  passengers." 

"  No,"  said  John,  "  I'm  determined  not  to  do  any  such 
thing." 

"  You  will  go  climbing  up  the  rigging,  or  mounting  up 
to  some  other  place,  where  no  gentlemen,  but  only  boys, 
ever  try  to  go." 

"No,"  said  John,  "I'm  determined  to  keep  always  in 
the  places  where  I  see  other  passengers  go." 

"  You  and  Flippy  will  get  to  quarreling  with  each  other, 
or  with  the  other  boys  or  girls,  about  your  turns  at  the 
swing." 

One  of  the  sailors  had  rigged  up  a  swing  for  the  amuse- 


LAWRENCE'S  MANAGEMENT.  71 

ment  of  the  children  among  the  passengers,  by  means  of 
rope  suspended  to  a  beam,  which  was  extended  from  the 
top  of  the  saloon  to  the  bulwarks,  over  the  main  deck. 

"  No,"  replied  John,  "  we  won't  quarrel  at  all.  We'll 
take  our  turns  fairly." 

"  Well,  at  any  rate,  you'll  be  sure  to  get  engaged  in  some 
foolery  or  other,"  said  Lawrence, "  and  Flippy  is  so  strict 
that  he  will  decide  against  you  if  you  do.  We  might 
take  Flippy  in  with  us  in  the  plan,  if  he  likes." 

"  Yes,"  said  Flippy,  eagerly, "  take  me  in — take  me  in." 

"  And  then  John  will  have  to  be  judge  if  I  accuse  you 
of  any  thing,"  said  Lawrence. 

"  Yes,"  said  John, "  I'll  be  judge  in  his  case." 

"And  you  must  watch  each  other,"  said  Lawrence,  "when 
I  am  not  by,  and  I'll  be  judge  in  those  cases.  You  see  we 
want  to  get  all  the  money  we  can  for  the  excursion." 

The  boys  agreed  to  this,  and,  feeling  a  desire  to  see  how 
it  looked  after  dark  on  deck,  they  went  out  of  the  saloon, 
leaving  Lawrence  alone.  As  they  walked  away,  he  said 
to  himself,  with  a  smile  of  satisfaction  on  his  face, 

"  I  don't  think  I  shall  actually  collect  many  fines  from 
them,  but,  on  the  contrary,  shall  probably  have  several  to 
pay  myself;  but  if  I  can  induce  the  boys  to  watch  each 
other,  and  consent  good-humoredly  to  be  watched  and 
checked  by  me  in  their  boyishness,  during  the  voyage, 
just,  by  being  fined  myself  now  and  then  a  few  cents  for  a 
peccadillo  or  a  misdemeanor,  it  will  be  one  of  the  best  in- 
vestments of  petty  cash  I  ever  made. 


V2  THE    FIRE    IN   THE    STREET. 


CHAPTER  VIL 

THE    FIRE    IN   THE    STREET. 

FLIPPY  had  not  taken  any  very  deep  interest  in  Law- 
rence's explanation  of  the  philosophy  of  the  burning  of  a 
candle,  though  he  had  listened  tolerably  attentively,  and 
had  answered  pretty  well  the  questions  which  Lawrence 
had  asked,  and  had  even  asked  some  questions  himself, 
showing  that  his  curiosity  on  the  subject  was  at  least  par- 
tially awakened.  But  Lawrence  was  well  aware  that  in 
respect  to  the  interest  of  children  in  the  acquisition  of 
knowledge,  as  well  as  to  their  progress  and  improvement 
in  all  respects,  as,  indeed,  it  is  in  respect  to  every  thing 
desirable  that  we  wish  to  obtain  from  others,  to  be  thank- 
ful for  little  is  the  best  way  to  get  more. 

Accordingly,  for  a  few  days  after  this  Lawrence  said 
nothing  to  either  of  the  boys  about  the  philosophy  of  com- 
bustion, or  about  any  other  scientific  subject,  but  talked 
to  them,  and  especially  to  Flippy,  about  what  they  saw 
around  them  on  board  the  ship,  explaining  to  them  the  ac- 
tion and  use  of  all  the  various  fixtures  and  contrivances 
which  they  observed  upon  the  deck  and  about  the  rigging. 
He  showed  them  the  boats,  eight  or  ten  in  number,  which 
were  placed  along  the  sides,  and  pointed  out  the  ways  in 
which  they  were  suspended  and  secured,  so  that  they 
should  at  once  be  out  of  the  way  of  the  passengers,  and 
safe  from  the  shocks  of  the  seas,  and  at  the  same  time  so 
suspended  by  tackles  and  blocks  upon  turning  cranes, 
called  davits,  that  they  could  be  swung  out  over  the  ship's 
side  and  let  down  into  the  water  at  very  short  notice,  and 


ON   DECK.  73 

in  a  very  rapid  manner,  in  case  any  accident  should  hap- 
pen requiring  the  use  of  them. 

Some  of  these  boats  were  bottom  upward,  and  were  fully 
furnished  with  oars,  sails,  water-casks,  and  every  thing  else 
which  could  be  required  in  case  of  emergency,  all  care- 
fully lashed  in  their  places  and  otherwise  secured,  and  pro- 
tected, moreover,  by  the  bottom  of  the  boat,  which  served 
as  a  roof  over  them. 

He  also  showed  them  the  compasses,  of  which  there  were 
several  along  the  main  deck,  and  one  upon  the  bridge 
which  led  across  from  one  paddle-box  to  another,  for  the 
walk  of  the  captain  and  the  pilot.  He  also  took  them  both 
about  from  place  to  place,  and  asked  them  a  great  many 
questions  about  what  they  observed,  to  see  if  they  could 
find  out  what  the  different  things  were,  and  what  they 
were  for ;  and  when  they  did  not  know  and  could  not  find 
out,  he  explained  to  them,  if  he  knew,  what  the  thing  was  or 
was  for,  and,  if  not,  he  said  frankly  that  he  did  not  know. 

"  We  must  ask  some  of  the  officers,"  said  John,  in  one 
such  case. 

There  were  a  number  of  officers  to  be  seen  walking  to 
and  fro,  at  their  posts,  in  various  parts  of  the  deck.  They 
were  known  by  a  kind  of  uniform  cap  which  they  wore. 

"  No,"  replied  Lawrence,  "  we  must  find  out  in  some 
other  way  than  that.  It  is  against  the  rules  of  etiquette 
on  board  a  steam-ship  like  this  to  ask  questions  of  the  offi- 
cers and  men  while  they  are  on  duty." 

So  saying,  Lawrence  pointed  to  an  inscription  on  the 
brass  covering  of  one  of  the  compasses,  saying  that  passen- 
gers were  requested  not  to  hold  conversation  with  the  offi- 
cers when  on  duty. 

"  But  I  saw  one  of  the  passengers  talking  with  an  offi- 
cer," said  Flippy. 

"  Yes,"  replied  Lawrence,  "  all  such  rules  have  excep- 
D 


74  THE    FIRE    IN   THE    STREET. 

tions.  He  may  have  been  an  acquaintance  of  the  officer, 
and  so  may  have  felt  himself  authorized  to  speak  to  him. 
Or  he  may  have  been  inconsiderate,  or  ignorant  of  the  rule, 
and  the  officer  would  not  refuse  to  answer  him,  not  willing 
to  be  rude." 

"  I  don't  see  what  harm  there  could  be  in  any  of  them 
just  answering  a  question,"  said  Flippy.  "It  would  not 
take  him  but  a  minute." 

"  It  would  only  take  him  a  minute  to  answer  one  ques- 
tion," said  Lawrence,  "but  he  would  have  an  immense 
number  to  answer  if  every  body  was  at  liberty  to  ask 
them.  You  see  at  every  voyage  they  take  on  board  sev- 
eral hundred  fresh  passengers,  nearly  all  of  them  very  ig- 
norant, and  full  of  curiosity  about  every  thing  they  see ; 
and  if  it  was  understood  that  they  might  all  ask  as  many 
questions  as  they  pleased,  the  time  of  the  ship's  company 
would  be  half  taken  up  in  answering,  over  and  over  again, 
the  same  inquiries.  And  they  are  under  no  obligation  to 
do  this.  What  we  pay  our  passage-money  "for  is  to  be 
conveyed  across  the  Atlantic,  not  to  be  taught  the  myste- 
ries of  the  rigging  and  management  of  the  ships." 

John  kept  a  journal.  It  was  a  pictorial  journal.  He 
pasted  pictures  in  it,  such  as  he  could  find,  that  illustrated 
the  scenes  and  incidents  that  he  met  with,  and  then  wrote 
brief  descriptions  under  them. 

When  Flippy  saw  this  journal  of  John's,  he  said  he 
wished  that  he  had  one.  If  he  had  thought  of  such  a 
thing,  he  said,  he  would  have  bought  him  a  book  for  it  in 
New  York.  Lawrence  told  him  that  if  he  chose  he  could 
begin  his  journal  on  separate  pieces  of  paper  while  he  was 
at  sea,  and  then  he  could  buy  a  book  at  Liverpool  and 
paste  them  in  for  the  beginning  of  his  book. 

"But  they  won't  look  like  the  rest  of  the  book,"  said  Flip- 
py, "if  they  are  written  on  different  papers  and  pasted  in." 


THE    JOGGLING.  75 

"  Then  you  can  copy  them  in,"  said  Lawrence.  "  That 
won't  be  much  trouble." 

"  No,"  replied  Flippy  ;  "  but  I  haven't  any  pictures." 

"I  can  give  you  some  pictures,"  rejoined  Lawrence — 
"  enough  to  last  through  the  voyage.  You  will  not  want 
many  till  we  get  to  England,  for  before  long  we  shall  prob- 
ably have  rough  weather,  and  then  you  can't  write." 

"  The  tables  tremble  so  every  where,"  said  John, "  that 
it  is  very  hard  to  write  now." 

"  True,"  replied  Lawrence ;  "  but  the  more  energy  and 
perseverance  you  show  in  overcoming  such  difficulties  as 
that,  the  more  merit  there  is,  and  the  more  you  will  value 
your  journal  in  time  to  come." 

"  But  the  writing  does  not  look  well,"  <said  John ;  "  my 
hand  trembles  so  much." 

"  True,"  said  Lawrence ;  "  but  that  is  no  matter.  Any 
badness  of  writing  which  comes  from  carelessness  on  your 
part  would  be  disagreeable  to  look  at  afterward,  because 
it  would  be  connected  with  disagreeable  associations  in 
your  mind.  But  any  tremor  in  the  writing  caused  by  the 
jarring  motion  of  the  ship  will  only  recall  the  voyage  to 
your  mind,  and  the  tremendous  working  of  the  floats  of 
the  paddle-wheels  in  the  water — which,  by  striking  the 
water  with  such  immense  force  and  in  such  rapid  succes- 
sion, cause  the  jarring — and  so  will  make  your  book  all  the 
more  interesting  and  valuable." 

John  very  readily  assented  to  this  view  of  the  case,  but 
Flippy  said  that  if  he  copied  his  writing  into  a  book,  when 
he  got  on  land,  there  would  be.  no  jar  in  the  writing.  John, 
however,  removed  this  difficulty  by  saying  that  he  would 
stand  by  the  table  and  joggle  it  for  him,  if  he  wished,  while 
he  was  writing. 

So  Lawrence  gave  Flippy  a  small  picture  which  he  select- 
ed from  among  several  which  he  had  laid  by  for  such  pur- 


76  THE    FIEE    IN   THE    STEEET. 

poses.  It  was  a  picture  of  some  boys  making  a  fire  in  the 
street.  Or,  as  Lawrence  expressed  it,  it  was  a  picture  of 
oxygen  combining  with  hydrogen  and  carbon  at  a  high 
temperature. 

"And  I  advise  you,"  said  Lawrence,  "to  write  those 
words  under  your  picture  as  the  scientific  name  of  it.  You 
can  put  with  them  any  additional  explanations  you  choose. 
It  will  help  you  remember  what  you  have  learned,  and  will 
also  show  you  in  after  years  that  at  the  time  when  you 
commenced  writing  your  journal  you  were  also  beginning 
to  study  science." 

Flippy  assented  readily  to  this  proposal.  So  he  attached 
the  picture,  by  means  of  a  little  gum  at  the  corners,  to  the 
top  of  the  paper,  and  wrote  under  it  the  words,  as  nearly  as 
he  could  recollect  them,  which  Lawrence  had  suggested, 
with  some  additional  explanations  of  his  own — thus: 


FIRE   IN   A   STREET. 


JOURNAL   BEGUN.  77 

This  looks  like  a  picture  of  some  boys  building  a  fire  in 
the  street  of  a  pretty  large  town,  but  it  is  really  a  picture 
of  oxygen  devouring  carbon  and  hydrogen.  The  boys 
only  heated  up  a  little  of  the  carbon  and  hydrogen,  so  that 
the  oxygen  could  begin.  I  know  that  the  place  is  in  a 
pretty  large  town,  because  there  is  an  omnibus  going 
along. 

When  Lawrence  saw  this  work  he  was  very  much 
pleased  with  it.  It  is  true  that  the  writing  was  not  very 
good,  partly  on  account  of  the  tremor  of  the  ship,  and 
partly  on  account  of  the  fact  that  Flippy,  who  had  never 
taken  much  interest  in  respect  to  any  thing  in  the  way  of 
study,  had  not  learned  to  write  very  well.  But  Lawrence 
was  pleased,  because  it  showed  that  Flippy  had  listened, 
and  had,  in  a  measure,  understood  what  he  had  explained 
to  him  in  respect  to  the  true  nature  of  combustion ;  and 
he  felt  encouraged  to  think  that  he  might,  perhaps,  in  the 
course  of  the  voyage,  lead  him  to  feel  a  considerable  de- 
gree of  interest  in  acquiring  at  least  one  kind  of  knowl- 
edge, and  that  this  might  be  the  beginning  of  awakening 
in  him  a  love  for  other  kinds. 

At  any  rate,  it  was  an  experiment  upon  mind  that  he 
was  making,  and  Lawrence  took  as  great  an  interest  in  ex- 
perimenting upon  mind  as  in  watching  the  operation  of 
causes  and  effects  in  the  material  world. 

Lawrence  did  not  openly  praise  Flippy's  work  when 
it  was  shown  to  him,  but  Flippy  saw  very  clearly  that  he 
was  satisfied  and  even  pleased  with  it.  This  greatly  en- 
couraged him,  and  made  him  quite  ready  to  undertake  any 
thing  new  which  Lawrence  might  propose.  He  was,  how- 
ever, somewhat  disconcerted  at  the  result  of  showing  his 
production  to  his  mother.  He  took  it  to  heFwhen  she  was 
sitting  on  the  deck,  under  the  shelter  of  one  of  the  paddle- 


78  THE    FIRE    IN    THE    STREET. 

9 

boxes,  in  company  with  one  of  her  fashionable  friends,  both 
being  well  wrapped  up  in  cloaks  and  mufflers.  Mrs.  Gray 
looked  at  the  picture  a  moment,  read  what  was  written 
under  it,  and  then,  holding  it  so  that  the  other  lady  could 
see  it,  she  said, 

"The  picture  is  pretty  enough,  isn't  it,  Maria?  But 
then  the  writing  ! — I'm  quite  ashamed  of  Flippy 's  writing. 
I  really  believe  I  shall  have  to  change  his  school.  He  does 
not  seem  to  improve  in  his  writing  at  all." 

She  proceeded  to  read  what  Flippy  had  written,  aloud, 
to  her  friend,  and  then  asked  Flippy  who  told  him  to  write 
such  things  as  that.  Flippy  said  it  was  Mr.  Wollaston. 

"  Well,"  said  she,  handing  him  back  the  paper, "  it  may 
be  all  very  well  for  what  I  know,  but  it  seems  to  me  to  be 
only  learned  nonsense."  Flippy  took  his  paper  and  went 
away  quite  disconcerted.  He  resolved  that  after  that  he 
would  show  all  that  he  did  to  Lawrence,  but  no  more  of  it 
to  his  mother. 


EXPRESSING   A   PRINCIPLE.  79 


CHAPTER 

THE    THREE    RECAPITULATIONS. 

ONE  morning,  a  few  days  after  this,  when  Lawrence  and 
the  two  boys  had  been  on  the  quarter-deck  together  watch- 
ing the  operation  of  heaving  the  log  at  four  bells — that  is, 
at  ten  o'clock — and  had  then  taken  their  seats  together  on 
one  of  the  settees  on  the  deck,  which  were  placed  alongside 
the  skylight,  Lawrence  told  Flippy  that  he  thought  what 
he  had  written  about  the  Fire  in  the  Street,  when  copied 
handsomely  in  his  journal,  would  make  a  very  good  begin- 
ning for  it. 

"And  what  you  said  in  it  of  your  own  accord,"  he  added, 
"  gave  a  very  good  account  of  the  substantial  nature  of 
combustion.  You  expressed  the  principle  very  well  indeed, 
and  very  correctly,  and  it  shows  that  you  paid  attention 
to  what  I  explained  to  you  about  it,  and  that  you  under- 
stood it  very  well." 

Flippy  was  much  pleased  with  -the  idea  of  his  having 
been  able  to  "  express  a  principle." 

"I  don't  know,"  continued  Lawrence,  "but  that  you  and 
I  might  make  a  recapitulation  of  all  I  have  taught  you  on 
the  subject." 

"  Well,"  said  Flippy,  in  a  tone  of  alacrity  and  pleasure, 
"  we'll  do  it." 

He  had  no  idea  at  all  what  a  recapitulation  was,  but  he 
thought  it  sounded  as  if  it  was  something  that  he  would  like 
to  make,  if  he  could. 

Lawrence  explained  to  the  boys  that  to  make  a  recapitu- 
lation of  any  instruction  or  information  you  have  received 


80  THE    THREE    BE  CAPITULATIONS. 

is  to  state  the  substance  of  it,  as  you  understand  it,  in  your 
own  words,  in  the  best  way  you  can.  He  then  added : 

"  I'll  tell  you  what — I  have  a  plan  to  propose.  I  will 
explain  once  more  what  I  have  told  you  about  the  grand 
part  that  oxygen  plays  in  all  the  changes  taking  place  in 
nature,  and  we  will  all  three  write  a  recapitulation  of  the 
principles ;  and  the  one  that  writes  the  best  one  shall  have 
a  prize.  I  will  buy  the  prize  when  we  get  to  Liverpool, 
and  it  shall  be  given  to  the  one  who  writes  the  best  reca- 
pitulation." 

"Ah!  but  that  won't  be  fair,"  replied  Flippy.  "Of 
course  you  can  write  the  best  one.  I  never  wrote  a  reca- 
pitulation in  my  life.  Even  John  can  write  a  great  deal 
better  one  than  I  can." 

"Yes,  but  we  will  make  allowance  for  our  different  ages 
and  abilities,"  said  Lawrence ;  "  it  shall  be  a  kind  of  handi- 
cap." . 

The  boys  did  not  either  of  them  know  what  a  handicap 
was.  Lawrence  explained  to  them  that  it  was  a  term  used 
in  racing,  and  that  it  denoted  an  allowance  made  for  the 
several  horses  on  account  of  the  difference  between  them  in 
respect  to  certain  conditions  which  would  affect  the  result 
of  the  race.  The  allowance  was  made  in  order  to  give 
each  one  as  nearly  as  possible  the  same  chance  in  the  trial. 

"  We  will  have  the  major  for  umpire,"  said  Lawrence, 
"  and  he  shall  make  the  allowances  for  our  different  ages 
and  capacities ;  so  that  he  will  have  to  decide,  not  which 
is  absolutely  the  best  recapitulation,  but  which  is  the  best 
for  the  one  who  wrote  it,  considering  his  age  and  his  op- 
portunities for  learning." 

"  Agreed  !"  said  John ;  "  but  what  shall  the  prize  be  ?" 

"  Something  that  I  will  buy  in  Liverpool,"  said  Law- 
rence, "when  we  arrive  there.  I  will  get  you  a  little 
compass,  or  a  pencil-case,  or  something  like  that." 


PEIZE    OFFERED.  81 

Flippy  said  he  should  prefer  a  compass.  He  had  want- 
ed a  little  compass,  he  said,  ever  so  long. 

"  But  then,"  he  added,  somewhat  mournfully,  "  I  don't 
suppose  there  is  much  chance  for  me  to  get  the  prize." 

"We  can't  tell,"  said  Lawrence.  "The  major  will  make 
full  allowance  for  your  being  the  youngest,  and  not  having 
had  much  experience  in  such  work." 

The  arrangement  having  been  thus  made,  Lawrence  ex- 
plained again  to  the  boys,  in  the  course  of  several  conver- 
sations which  he  held  with  them  during  that  and  the  fol- 
lowing day,  what  he  had  already  told  them  about  the 
agency  of  oxygen  in  the  great  revolving  cycle  of  change 
that  was  going  on  incessantly  in  nature  in  connection  with 
the  principle  of  life — how  that  in  some  mysterious  way  the 
sun,  by  a  wonderful  power  inherent  in  its  beams,  separates 
the  two  great  elements,  carbon  and  hydrogen,  from  their 
combination  with  oxygen  in  the  air,  and  in  the  moisture 
which  floats  in  it,  or  which  is  drawn  up  by  the  rootlets 
from  the  ground ;  how  these  substances  are  held  thus  be- 
yond the  reach  and  power  of  oxygen  in  the  tissues  of 
plants — and  in  the  tissues  of  animals  when  the  plants  are 
eaten  by  animals — so  long  as  the  principle  of  life  contin- 
ues ;  and  that  at  length,  when  this  ceases  to  protect  them, 
the  oxygen  takes  possession  of  them  again. 

The  oxygen,  moreover,  as  he  farther  explained,  recovers 
possession  of  these  substances  by  slow  degrees  and  in  a 
very  gentle  manner,  so  long  as  they  are  kept  at  the  ordi- 
nary temperature  of  the  air ;  but  very  rapidly,  and  with 
the  most  intense  and  violent  action,  when  they  are  raised 
to  a  certain  degree  of  heat.  But,  in  whichever  way  it  re- 
covers possession  of  them,  it  carries  them  off  in  gases  into 
the  air,  and  in  water  into  the  ground,  and  keeps  strong 
hold  of  them,  until  at  length  the  sun,  by  his  mysterious 
power  act-ing  in  the  leaves  of  plants,  recovers  them,  and 

D  2 


82  THE    THREE    RECAPITULATIONS. 

converts  them  again  to  the  purposes  of  vegetable  life, 
whence  they  afterward,  when  released  from  this  protec- 
tion, are  seized  again  by  the  free  oxygen  floating  in  the 
atmosphere,  or  mingling  with  the  portion  of  air  which  is 
generally  contained  in  water,  till  they  are  again  separated 
from  it,  in  fresh  leaves,  by  other  beams  from  the  sun ;  and 
so  the  change  goes  on  in  an  eternal  alternation. 

Lawrence  ought  to  have  explained  to  the  boys,  if  he  did 
not,  that  what  he  had  taught  them  was  only  a  very  gen- 
eral view  of  the  great  leading  principle  which  governs  the 
phenomena  of  life  on  the  one  hand,  as  revived,  sustained, 
and  perpetuated  upon  the  earth  through  the  instrumental- 
ity of  the  sun  in  deoxydizing  carbon  and  hydrogen,  and 
of  death,  decay,  and  combustion  as  a  reoxydizing  process. 
This  is,  indeed,  a  great  leading  principle,  and  one  which  it 
is  very  important  that  all  students  of  nature  should  under- 
stand, for  it  is  a  fundamental  one,  and  the  knowledge  of  it 
aids  us  very  much  in  all  subsequent  studies,  and  assists  us 
more  clearly  to  comprehend  and  to  systematize  in  our  own 
minds  the  other  truths  and  principles  which  we  may  learn. 
But  this  principle,  though  a  fundamental  one,  is  only  a  gen- 
eral one.  In  its  actual  operation  it  is  involved  in  an  end- 
less number  of  complications  and  details,  in  which  a  vast 
variety  of  substances  are  formed,  and  after  fulfilling  in  the 
most  various  ways  their  several  curious  functions,  are  dis- 
solved and  disappear,  while  the  elements  of  which  they 
are  composed  enter  into  new  combinations,  form  new  sub- 
stances, which  fulfill  new  functions,  and  then  dissolve  and 
disappear  as  their  predecessors  had  done,  and  so  on  in  an 
endless  maze  which  it  is  utterly  impossible  that  any  human 
intelligence  should  ever  fully  unravel.  As  we  advance  in 
the  exploration  of  this  field,  the  more  we  learn  and  the 
more  we  know,  the  more  glimpses  we  obtain  of  mysterious 
complications  beyond. 


WRITING    ON   DECK.  85 

Lawrence  had  explained  the  general  principle  to  the  boys 
before,  but  when  the  plan  was  proposed  of  writing  recapit- 
ulations for  a  prize,  he  explained  it  again  in  a  somewhat 
more  simple  manner  than  I  have  done,  and  with  many  ref- 
erences to  common  facts  respecting  the  sun  and  life  as  de- 
oxydizing,  and  decay  and  combustion  as  reoxydizing  agents. 
He  also  used  the  terms  hydrogen,  carbon,  and  hydrocarbon 
very  frequently  and  familiarly,  so  as  to  accustom  the  boys 
to  them,  and  to  associate  the  meaning  of  them  with  the 
sounds  in  their  minds. 

After  having  in  this  way  made  the  subject  as  plain  as 
he  could  to  the  boys,  he  made  the  arrangement  with  them 
that  they  should  write  their  recapitulations  the  next  day 
before  dinner,  and  then  refer  them  to  the  major  for  his  de- 
cision between  dinner  and  tea.  Lawrence  told  the  boys 
that  they  need  not  undertake  to  write  a  great  deal.  It 
was  only  a  brief  statement  of  the  general  principles  that 
was  required. 

John  and  Flippy  determined  to  write  their  recapitula- 
tions upon  the  deck,  where  they  could  look  out  occasion- 
ally over  the  water  while  they  were  writing,  to  see  if  any 
ships,  or  whales,  or  icebergs  came  in  sight.  Lawrence 
wrote  his  in  a  small  place,  like  a  room,  below,  which  was 
called  the  gentlemen's  cabin,  and  which  contained  a  large 
table,  with  seats.  They  all  finished  their  work  before 
luncheon,  which  was  at  noon;  but,  as  the  major  seemed 
to  be  engaged  with  other  gentlemen  after  luncheon,  they 
concluded  to  wait  until  dinner-time  before  they  mentioned 
the  subject  to  him,  and  then  to  ask  him  if  he  was  willing 
to  act  as  umpire,  and,  if  so,  if  it  would  be  convenient  for 
him  to  hear  the  articles  which  had  been  written,  and  de- 
cide which  was  the  best,  between  dinner  and  tea. 

This  arrangement  was  accordingly  made ;  and  when  the 
tables  had  been  cleared  after  dinner,  they  all  four  went  to 


86  THE    THREE    RECAPITULATIONS. 

the  end  of  one  of  the  long  tables,  at  the  farther  part  of  the 
saloon,  where  they  could  be  together  and  be  undisturbed. 

"Well,"  said  the  major,  as  soon  as  they  were  seated, 
"  what  is  the  business  before  this  meeting  ?" 

Lawrence  stated  the  case,  saying  that  they  had  agreed 
to  write,  for  a  prize,  a  recapitulation  of  the  principles  which 
lay  at  the  foundation,  in  a  chemical  point  of  view,  of  the 
great  alternation  and  rotation  of  life,  death,  and  decay,  and 
that  they  wished  him  to  hear  what  had  been  written,  and 
decide,  as  umpire,  which  of  the  writers  deserved  the  prize. 

"H'm !"  said  the  major,  if  making  the  inarticulate  sound 
represented  in  that  way  can  be  called  saying  any  thing. 
"  It  seems  to  me  that  the  boys  have  hardly  a  fair  chance 
with  you,  Lawrence,  in  such  a  contest  as  that." 

"  Ah  !  but  you  see  it  is  a  kind  of  handicap,"  said  Law- 
rence. "  You  are  to  make  allowances." 

"  Oh !    A  handicap,  is  it  ?".  rejoined  the  major. 

"  Yes,"  replied  Lawrence ;  "  you  are  to  make  proper  al- 
lowances for  differences  of  age  and  opportunities  for  in- 
struction. The  question  is  not  which  statement  is  abso- 
lutely the  best,  but  which  is  the  best  considered  as  a  per- 
formance of  the  one  who  made  it." 

"Very  well,"  said  the  major;  "that  makes  it  all  right. 
So  go  ahead  with  your  reading.  I  shall  not  be  long  in 
deciding  after  I  have  heard  the  documents.  We  will  Hear 
Flippy's  first,  as  he  is  the  youngest." 

So  Flippy  began  at  once,  and  read  his  paper  as  follows : 

RECAPITULATION. 


BY 

PHILIP  GRAY. 


Oxygen  is  something  that  you  can  not  see  by  itself.  It 
is  in  a  great  many  things.  You  can  see  the  things^  but 
you  can  not  see  the  oxygen. 


WORD    MISSPELLED.  87 

It  has  a  great  appetite  for  a  great  many  things.  They 
call  the  appetite  a  finnity.  The  principal  things  it  likes 
best  are  carbon  and  hydrogen;  but  it  can  eat  even  into 
iron. 

The  sun  gets  the  carbon  and  hydrogen  away  from  the 
oxygen  somehow  or  other  in  the  leaves  of  plants  when 
they  are  growing.  It  keeps  the  carbon  and  hydrogen,  and 
makes  hydrocarbons  of  them,  and  turns  the  oxygen  off 
loose. 

By-and-by  the  oxygen  finds  the  hydrogen  and  carbon, 
and  eats  them  up  again.  If  they  set  the  things  on  fire, 
the  oxygen  eats  them  up  very  fast,  and  makes  a  great 
blaze. 

Here  Flippy  finished  his  reading,  and  looked  up  to  see 
how  the  major  seemed  to  have  taken  it. 

"  Good !"  said  the  major.  "  Now  hand  me  the  paper  and 
let  me  look  at  the  writing." 

Flippy  gave  the  paper  into  the  major's  hand,  and  the 
major  cast  his  eye  over  it.  He  observed  that  Flippy  had 
taken  pains  to  write  as  well  as  he  could,  and  that  the  lines 
were  even  and  the  letters  well  formed,  so  far  as  the  trem- 
ble of  the  ship  would  permit.  He  observed,  it  is  true,  that 
the  word  affinity  was  spelled  afinnity,  but  he  said  nothing 
about  it. 

After  the  major  had  returned  the  paper,  John,  who  had 
looked  over  Flippy  while  he  had  been  reading  it,  remarked 
that  there  was  one  fault ;  he  had  spelled  the  word  affinity 
wrong. 

"  Did  you  tell  him  how  to  spell  the  word  ?"  asked  the 
major,  looking  toward  Lawrence. 

Lawrence  said  he  did  not. 

"  Then  how  should  he  know  how  to  spell  it  ?"  asked  the 
major.  "I  think  that  is  no  fault  at  all — that  is, I  mean,  no 


88  THE    THKEE    EECAPITULATIONS. 

fault  of  Flippy 's.    Now,  John,  let  us  hear  yours."    So  John 
read  as  follows : 

ABOUT  OXYGEN. 

The  most  common  thing  in  the  world  is  oxygen.  Oxy- 
gen is  not  a  thing  exactly,  but  a  kind  of  substance  out 
of  which  a  great  many  things  are  made.  It  is  an  ele- 
ment. 

When  it  is  obtained  by  itself  it  is  a  gas  which  may  be 
kept  in  a  glass  jar.  Almost  any  thing  that  is  put  in  it  and 
set  on  fire  burns  furiously. 

It  has  a  great  affinity  for  almost  all  substances,  and 
when  they  are  only  moderately  warm  it  dissolves  them,  or 
combines  with  them  slowly.  When  they  are  very  hot  it 
combines  with  them  very  fast  and  very  furiously,  and 
gives  out  heat  and  light.  This  is  what  we  call  combus- 
tion. 

The  oxygen  that  there  is  in  rocks,  and  sand,  and  gravel 
is  already  combined  with  other  substances — enough  to 
have  its  fill — and  so  it  lies  quiet.  So  it  is  with  the  oxygen 
which  exists  in  the  water  of  the  sea,  and  of  lakes  and  riv- 
ers. 

But  the  oxygen  that  is  in  the  air  is  free,  and  it  goes 
about  trying  to  find  something  to  devour.  It  devours  all 
the  dead  leaves  and  dead  wood  in  the  forests,  and  all  the 
dead  bodies  that  are  left  on  the  ground.  It  even  gnaws 
into  iron,  and  so  they  call  it  a  great  devourer. 

This  was  the  end  of  John's  recapitulation.  It  then  be- 
came Lawrence's  turn.  He  opened  his  paper  and  com- 
menced as  follows : 


LIFE  AND  OXYGEN; 

OR, 

THE    ECONOMY    OF   NATURE    IN    RESPECT    TO   THE    ROTATION 
OF   LIFE,  GROWTH,  DEATH,  AND   DECAY. 

1.  The  substance  which  takes  precedence  of  all  others  in 
the  economy  of  nature,  as  observed  by  man,  on  the  surface 
of  the  earth,  both  in  respect  to  its  abundance  as  to  quan- 
tity, and  to  the  extent  and  importance  of  the  functions  it 
fulfills,  is  oxygen. 

2.  Oxygen  has  a  very  strong  affinity  for  most  other  ele- 
ments.    It  combines  with  them  with  great  readiness,  and 
sometimes  with  great  avidity,  and  holds  them  in  combina- 
tion with  great  force.     It  may  be  called  the  great  strong- 
holder  of  nature.    There  is  another  remarkable  substance, 
which  may  be  called  the  great  weak-holder  /  but,  as  I  have 
not  yet  described  this  weak-holding  substance  to  the  boys, 
I  do  not  bring  it  into  this  recapitulation. 

3.  The  power  of  the  sun,  as  transmitted  to  the  earth  in 
its  radiations,  and  acting  in  connection  with  the  principle 
of  life,  is  the  great  antagonistic  force  with  which  oxygen 
has  to  contend. 

4.  The  power  of  the  sun,  in  taking  substances  away  from 
their  combinations  with  oxygen,  is  exercised  chiefly  in  the 
leaves  of  plants,  while  the  plants  are  growing. 

5.  The  two  chief  substances  which  it  thus  takes  away 
are  carbon  and  hydrogen.     It  takes  the  hydrogen  from  the 
water  which  comes  up  from  the  ground  through  the  roots, 
or  floats  around  the  leaves  in  the  air;  for  this  water  is 
composed  of  oxygen  and  hydrogen.     It  takes  the  carbon 
from  a  certain  substance  called  carbonic  acid,  which  exists 
in  small  quantities  both  in  water  and  in  the  air,  and  which 
is  composed  of  oxygen  and  carbon. 

6.  The  hydrogen   and  carbon,  thus  forcibly  separated 


90  THE    THREE    RECAPITULATIONS. 

from  the  oxygen  with  which  they  were  combined,  are 
formed  into  vegetable  tissues  or  vegetable  substances, 
which  remain  in  the  plants,  or,  when  the  plants  or  portions 
of  them  are  consumed  by  animals  as  food,  pass  into  the  an- 
imals, and  are  modified  there  in  various  ways,  being  pro- 
tected all  the  time  while  they  remain  parts  of  the  living 
system  from  being  taken  by  oxygen  again. 

7.  At  length,  when  the  plant  or  the  animal  dies,  or  when, 
before  they  die,  any  portions  of  these  substances  are  reject- 
ed from  the  living  organization,  so  that  the  carbon  and  hy- 
drogen are  no  longer  protected  by  the  principle  of  life,  the 
oxygen  floating  in  the  air  claims  them  again,  reunites  with 
them,  and  thus  reconstructs  carbonic  acid  and  water  with 
them,  and  in  this  form  carries  them  away.     When  the  ox- 
ygen recovers  these  substances  by  a  slow  and  gentle  ac- 
tion, as  it  does  at  ordinary  temperatures,  we  call  the  pro- 
cess decay.    When  the  process  is  rapid  and  violent,  as  it  is 
when  the  action  is  commenced  by  the  application  of  a  cer- 
tain degree  of  heat,  and  is  accompanied  by  the  develop- 
ment of  light  and  heat  produced  by  the  intensity  of  the 
force  with  which  the  combination  takes  place,  it  consti- 
tutes what  we  call  combustion. 

8.  In  whichever  way  the  oxygen  recovers  possession  of 
the  carbon  and  hydrogen,  it  carries  these  substances  off  in 
the  forms  of  carbonic  acid  and  water — which  it  produces 
by  combination  with  them — to  float  about  in  these  forms 
in  the  atmosphere,  or  to  be  absorbed  by  the  ground,  until 
the  sun  again  seizes  them  in  the  leaves  of  growing  plants 
and  recommences  the  same  never-ending  round. 

9.  Thus  the  general  principle  which  governs  the  great 
movement  of  life  and  growth  on  the  one  hand,  and,  on  the 
other,  of  death  and  decay,  which  follow  each  other  in  an 
endless  procession  in  the  economy  of  nature  on  the  surface 
of  the  earth,  is  that  of  the  deoxydation  of  carbon  and  hy- 


THE    DECISION.  91 

drogen  by  the  power  of  the  sun,  in  connection  with  the 
principle  of  life,  in  the  leaves  of  plants,  and  the  reoxyda- 
tion  of  them  after  death  by  a  rapid  and  violent  action  in 
combustion,  or  a  slow  and  gentle  one  in  decay. 

"That's  the  end,"  said  Lawrence,  looking  up  from  his 
paper  after  he  had  finished  the  reading  of  it. 

"  Yes,  I  think  it  ought  to  be,"  said  the  major.  "  It  is 
good  enough,  but  it  is  too  long.  And  now  as  to  the  boys. 
I  must  ask  them  some  questions,  so  as  to  know  what  allow- 
ances to  make.  Did  you  ever  study  chemistry,  Flippy  ?" 

Flippy-  said  he  never  had  studied  it  at  all.  He  did  not 
even  know,  he  said,  what  chemistry  was. 

"  And  did  you  know  nothing  about  all  this,"  asked  the 
major, "till  Lawrence  explained  it  to  you  on  this  voyage?" 

Flippy  said  he  did  not. 

The  major  then  asked  John  the  same  question.  John 
said  that  he  had  studied  chemistry  at  school,  and  had  heard 
a  course  of  lectures,  and  had  even  performed  some  experi- 
ments, but  that  he  had  never  heard  before  what  Lawrence 
had  explained  to  him  about  oxygen  and  the  sun. 

"  Then  I  think,"  said  the  major, "  that  in  respect  to  the 
prize,  the  question  is  between  you  and  Flippy.  As  for  Law- 
rence, he  is  nowhere.  His  article  is  nothing  for  him,  with 
all  the  study  he  has  had  at  the  scientific  school,  compared, 
to  what  either  of  yours  are  for  you.  And,  besides,  his  is  too 
long.  It  is  an  essay  rather  than  a  recapitulation.  As  to 
yours,  boys,  they  are  so  nearly  equal,  judged  on  the  handi- 
cap principle,  that  I  can't  undertake  to  distinguish  between 
them,  and  so  I  decide  that  Lawrence  must  give  you  both  a 
compass  when  we  arrive  at  Liverpool." 

The  boys  were  both  well  satisfied  with  this  decision,  but 
they  were  neither  of  them  better  satisfied  with  it  than 
Lawrence  was. 


92  ENOKMOUS   FORCE. 


CHAPTER  IX. 

ENORMOUS    FORCE. 

THE  force  transmitted  to  the  earth  from  the  sun,  and 
which  acts  in  the  leaves  of  plants  in  the  manner  described 
in  the  last  chapter,  comes  in  three  different  forms  or  kinds 
of  rays,  namely,  rays  of  light,  of  heat,  and  of  chemical  force. 
The  scientific  names  of  these  three  kinds  of  emanation  are, 

1.  The  luminous  rays. 

2.  The  calorific  rays. 

3.  The  actinic  rays. 

They  are  sometimes,  however,  designated  simply  as  light, 
heat,  and  actinism. 

It  is  very  possible  that  some  of  the  readers  of  this  book 
may  never  have  heard  of  this  last-named  kind  of  rays, 
namely,  the  actinic  rays,  and,  if  so,  I  advise  them  to  pause 
here  long  enough  to  fix  the  word  in  their  memories;  for 
the  word,  uncommon  as  it  is  in  ordinary  discourse,  is  used 
a  great  deal  in  the  scientific  works  that  you  will  read  as 
you  grow  older,  and  it  denotes,  moreover,  a  very  import- 
ant thing.  It  is,  for  example,  chiefly  by  the  power  of  the 
actinic  rays,  or  the  chemical  rays,  as  they  are  sometimes 
called,  that  the  image  is  fixed  upon  the  sensitive  paper  in 
photography.  It  is  commonly  said  that  the  image  is  fixed 
by  the  light,  which  is  not  strictly  true.  This  mode  of  speak- 
ing arises  from  the  fact  that  the  luminous  rays  and  the  ac- 
tinic rays  come  nearly  together  in  the  same  beam,  and  so 
people  generally,  not  distinguishing  between  the  two,  and 
perhaps  not  knowing  that  there  is  such  a  distinction,  call 
the  whole  radiation  light,  that  being  a  convenient  term, 
and  one  with  which  every  body  is  familiar. 


FIXING   IN  THE   MEMORY.  93 

The  photographers,  I  think,  generally  call  the  actinic 
rays  the  chemical  rays,  for  it  is  by  the  chemical  effects 
which  they  produce  that  they  are  chiefly  known  to  us.  It 
is  by  a  chemical  effect,  produced  on  the  sensitive  paper  in 
photography,  that  the  picture  is  produced. 

As  to  the  word  actinic,  a  very  good  way  to  fix  it  in  the 
memory  is  the  one  which  Lawrence  adopted  with  John 
and  Flippy  in  helping  them  to  remember  new  and  difficult 
words,  which  was  what  he  called  running  them  over  the 
tips  of  the  fingers.  He  said  that  a  very  excellent  way  into 
the  memory  was  by  the  tips  of  the  fingers.  The  method 
of  impressing  the  word  upon  the  memory  in  this  manner 
was  as  follows :  The  boy,  with  the  forefinger  of  his  right 
hand,  would  touch  the  thumb  of  his  left  hand,  speaking  at 
the  same  time,  in  a  very  distinct  and  emphatic  manner,  the 
word  actinic,  or  the  word,  whatever  it  might  be,  that  he 
wished  to  fix  in  his  mind.  Then  he  would  touch  the  tip 
of  the  forefinger  of  the  same  hand,  and  pronounce  the  word 
again,  and  so  on  with  all  the  fingers  of  that  hand  in  suc- 
cession. 

He  would  then  proceed  in  the  same  way  with  the  thumb 
and  fingers  of  the  right  hand,  touching  them  with  the  fore- 
finger of  the  left,  and  pronouncing  the  word  actinic  very 
distinctly  over  every  one.  In  this  way  he  would  pro- 
nounce the  word  ten  times,  and  this  would  be,  in  most 
cases,  a  very  effectual  means  of  familiarizing  him  with  the 
sound  of  it  and  fixing  it  in  his  memory.  I  advise  the 
readers  of  this  book  to  try  this  plan  with  any  new  and 
difficult  word  which  they  wish  to  make  themselves  re- 
member, commencing,  if  they  please,  with  the  word  ac- 
tinic, or  actinism. 

All  the  three  kinds  of  radiation  which  have  been  de- 
scribed above  mingle  in  their  action  on  the  leaves  of  trees 
and  plants  when  the  sun  is  shining  upon  them.  What 


94  ENORMOUS    FORCE. 

special  part  each  one  takes,  and  in  what  precise  way  they 
severally  act,  in  forcing  the  hydrogen  and  carbon  from  the 
oxygen,  is  very  imperfectly  understood ;  but  one  thing  is 
certain,  and  it  is  a  very  curious  and  important  thing  to 
understand.  It  is  this: 

That  the  radiation  from  the  sun  produces  its  effect  of 
separating  the  oxygen  from  the  carbon  and  hydrogen  by 
the  exercise  of  a  certain  amount  of  force,  and  that  this 
force — precisely  this  amount;  just  so  much  and  no  more — 
is  imparted  to  the  vegetable  substances  produced,  and  re- 
mains in  them  in  a  state  of  suspended  action,  as  it  were,  to 
be  given  out  again  in  the  form  of  heat,  or  in  some  other 
form,  when,  in  the  process  of  combustion  or  decay,  the  car- 
bon or  hydrogen  fall  back  into  the  possession  of  oxygen 
again. 

In  other  words,  the  force  by  which  a  particle  of  hydro- 
gen is  separated  from  the  particle  of  oxygen  in  the  leaf,  to 
help  make  of  it  a  hydrocarbon  in  the  plant,  is  stored  up 
in  the  plant,  and  precisely  that  amount  comes  into  action 
when  afterward  the  particle  of  hydrogen  is  again  united 
to  a  particle  of  oxygen. 

Just  as  when  the  string  of  a  bow,  in  a  bow-gun,  is  drawn 
back  and  hooked  over  its  peg,  the  force  with  which  it  was 
drawn  is  stored,  so  to  speak,  and  retained,  and  remains  in 
a  state  of  tension  and  suspense  until  the  string  is*  released, 
when  precisely  that  amount — no  less  and  no  more — is  given 
out  and  expended  in  impelling  the  arrow. 

This  effect  of  the  sun's  radiation  in  storing  up,  so  to 
speak,  a  definite  and  precise  amount  of  force  in  the  tissues 
produced  by  vegetation,  is  one  of  the  great  scientific  dis- 
coveries of  modern  times.  Lawrence  explained  it  to  John 
and  Flippy.  Flippy  said  that,  after  all,  he  did  not  under- 
stand it  very  well,  on  account  of  there  being  so  many  hard 
words.  Lawrence  told  him  that  he  could,  at  any  rate,  un- 


IN    THE    STATE-ROOM.  95 

derstand  it  in  this  form,  which  was  the  common  mode,  he 
said*  of  explaining  it — namely,  that  the  heat  from  the  sun 
which  comes  in  through  the  leaves  of  plants  is  stored  up 
in  the  wood  in  the  form  of  a  force  in  a  state  of  tension  ; 
that  it  remains  in  the  wood,  and  in  the  coal  into  which  the 
wood  becomes  transformed  when  buried  up  deep  in  the 
ground;  and  that  this  force  is  set  free  when  the  carbon 
and  hydrogen  again  fall  back  into  the  power  of  oxygen,  as 
they  do  with  great  rapidity  and  violence  when  the  wood 
is  burned. 

"  And  if  you  like,"  continued  Lawrence,  "  we  will  go 
down  into  the  engine-room  some  day,  and  see  the  furnaces 
where  the  firemen  are  at  work  delivering  up  the  carbon 
and  hydrogen  of  the  coal  to  the  oxygen  again,  and  so 
making  it  give  out  again  its  store  of  force  to  work  the  en- 
gine, and  drive  the  paddle-wheels,  and  so  carry  the  ship, 
and  all  of  us  who  are  on  board,  across  the  Atlantic  Ocean." 

Flippy  said  that  he  should  like  to  go  very  much,  if  they 
would  let  him. 

"I  will  see  the  engineer  and  ask  him,"  said  Lawrence. 
"  I  believe  he  likes  to  have  people  go  down  and  see  the 
machinery,  for  they  generally  give  him  a  little  fee  when 
they  come  up,  to  spend  for  the  benefit  of  the  men." 

One  morning,  about  an  hour  after  breakfast,  the  two 
boys  were  sitting  on  the  narrow  seat  in  the  state-room, 
eating  each  an  orange.  On  board  these  steamers  you  can 
have  as  many  oranges  as  you  like  by  just  asking  a  steward 
to  bring  them.  While  thus  engaged,  they  heard  the  voice 
of  one  of  the  passengers,  from  one  of  the  state-rooms  near, 
calling  to  a  steward  along  the  passage.  The  steward  an- 
swered, "  Coming,  sir,"  and  immediately  afterward  the  boys 
heard  the  following  conversation : 

"  What  o'clock  is  it,  steward  ?"  asked  the  passenger. 

"  Ten  minutes  past  ten,  sir,"  said  the  steward. 


96  ENORMOUS   FORCE. 

"  My  soul !"  exclaimed  the  man.  "  Just  a  good  time  for 
me  to  lose  my  breakfast." 

"  It  is  rather  late  for  breakfast,  sir,"  said  the  steward. 

The  custom  is  to  serve  breakfast  from  eight,  or  half  past 
eight,  to  ten,  during  which  time  the  passenger  can  order 
any  thing  that  he  pleases,  as  at  the  great  New  York  hotels, 
and  the  cooks  will  prepare  it  for  him  at  short  notice.  But 
after  ten  it  is  too  late.  The  cooks  and  stewards  then  are 
all  busy  in  preparing  for  luncheon,  which  is  to  be  on  the 
table  at  twelve;  and  as,  in  crossing  the  Atlantic  from 
west  to  east  in  a  swift  steamer,  there  is  only  about  an  hour 
and  a  half  between  ten  o'clock  and  noon,  and  as,  moreover, 
there  are  usually  some  hundreds  of  passengers  to  be  pro- 
vided for,  it  is  evident  that  they  have  no  time  to  waste  on 
those  who  are  too  indolent  to  be  ready  for  breakfast  in 
season. 

"But  I  must  have  something  for  breakfast,"  said  the 
man.  "  I  shall  die  if  I  can't  get  any  thing  to  eat." 

"  We  can  give  you  a  cup  of  tea,  sir,"  said  the  steward, 
"  and  a  slice  of  cold  meat,  but  it  is  rather  late  to  order 
any  thing  hot." 

Just  at  this  moment  Lawrence  appeared  at  the  door  of 
the  state-room,  and  told  the  boys  that  he  had  made  ar- 
rangements with  the  engineer  for  them  to  go  down  and 
see  the  engine,  and  that  they  were  to  go  immediately.  So 
the  boys  threw  their  orange-skins  out  through  the  port  into 
the  sea,  and  then,  after  wiping  their  fingers  on  a  towel, 
they  followed  Lawrence  to  the  deck. 

They  proceeded  at  once  to  the  place  near  the  middle  of 
the  ship  where  the  engine,  and  what  pertained  to  it,  and 
to  the  engineers,  were  situated.  There  was  a  large  opening 
through  the  deck,  twenty  or  thirty  feet  square,  guarded  by 
a  massive  brass  balustrade.  Looking  down  into  this  open- 
ing, the  boys  could  see  the  ponderous  machinery  moving 


THE    MACHINERY.  97 

with  prodigious  force,  the  immense  cranks  on  each  side  ris- 
ing and  falling  alternately,  and  carrying  around  the  main 
shaft,  which  passed  out  through  the  ship's  sides,  and  re- 
volved the  vast  paddle-wheels  attached  to  the  outer  ends 
of  them,  by  which  the  steamer  was  driven  through  the 
water  with  such  tremendous  force.  Some  of  the  innumer- 
able bearings  of  the  machinery  were  oiled  by  a  self-acting 
apparatus — a  little  pin  in  the  wheel  at  each  revolution 
opening  the  passage-way  and  allowing  a  small  portion  of 
oil  to  flow  out.  But  one  great  junction — the  one  in  which 
the  monstrous  iron  beams  worked  by  the  cylinders  below 
grasped  the  crank  and  carried  it  round — had  to  be  oiled 
by  a  man  who  stood  leaning  over  the  balustrade,  and 
poured  a  little  oil  into  a  brass  box  over  the  joint  from  an 
elegant  long-nosed  and  highly-polished  brass  oil-can.  The 
boys  wondered  at  the  dexterity  of  the  man  in  pouring  the 
oil  into  the  box  at  the  right  instant  as  it  came  up,  and  then 
suddenly  withdrawing  his  can  just  in  time  to  save  it  from 
being  knocked  out  of  his  hand  by  the  immense  beam  as  it 
went  over. 

Looking  down  over  the  balustrade,  they  could  see  a 
moving  mass  of  ponderous  machinery  extending  through 
three  stories  below,  with  floors  of  open  iron  work  forming 
galleries  between  them.  There  was  a  very  curiously  con- 
structed iron  stair,  very  steep,  which  led  down  among  all 
this  mechanism.  Away  down  at  the  bottom  there  was  a 
glimpse  of  many  fires  seen  dimly  through  the  moving  ma- 
chinery, and  of  half-naked  men  shoveling  coal  into  them. 

In  the  rear  of  this  opening  on  the  deck  was  a  large  in- 
closed space  covered  with  a  floor  formed  of  an  iron  grating, 
in  the  middle  of  which  was  a  round  opening  like  a  small 
well,  at  which  four  or  five  men  were  at  work  attending  to 
(the  bringing  up  of  ashes  and  cinders  from  the  fires  below. 
These  waste  products  were  brought  up  in  iron  buckets 

E 


98  ENORMOUS   FORCE. 

nearly  as  big  as  barrels,  which  were  raised  by  a  small  en- 
gine near,  driven,  doubtless,  by  power  derived  from  the 
main  engine.  They  seemed  to  come  up  from  a  great  depth. 
As  soon  as  one  came  to  the  surface,  it  was  seized  by  two 
men  standing  near,  unhooked  in  an  instant,  an  empty 
bucket  which  stood  ready  was  hooked  on,  and  at  the  same 
instant  the  two  men,  bracing  against  each  other  for  mutual 
support  in  sustaining  so  heavy  a  weight,  hurried  off  with 
the  full  bucket  to  the  side  of  the  ship,  and  emptied  it 
through  an  iron  shoot  into  the  sea.  They  then  carried 
the  bucket  back  to  the  well  in  time  to  take  the  next  full 
bucket  as  soon  as  it  reached  the  surface.  There  was  a 
fifth  man  in  the  gang,  whose  duty  it  was  to  attend  to  the 
little  engine,  and  shift  the  movement  according  as  the  ac- 
tion of  the  engine  was  required  to  bring  full  buckets  up  or 
to  let  empty  ones  down. 

The  boys  had  no  time  for  stopping  to  look  at  these 
things,  but  could  only  glance  at  them  as  they  passed  in 
following  Lawrence  to  the  engineer.  This  was,  however, 
of  no  great  consequence,  as  they  had  often  watched  these 
operations  before. 

Immediately  forward  of  the  great  opening  through 
which  the  machinery  was  seen  there  was  what  in  a  city 
would  be  called  quite  a  little  "  block"  of  state-rooms  be- 
longing to  the  engineer's  department.  They  were  ar- 
ranged in  two  rows,  with  a  passage-way  between  them. 
They  were  for  the  use  of  the  engineer  and  his  assistants, 
and  had  each  its  own  proper  inscription  in  gilt  letters  on 
the  door.  The  boys  found  the  chief  engineer  in  his  own 
room,  which  was  a  very  pretty  and  nicely-furnished  cabin, 
with  a  berth,  a  sofa,  a  desk  for  writing,  and  shelves  con- 
taining books  and  scientific  instruments.  It  presented  the 
appearance,  indeed,  of  quite  a  charming  little  study. 

The  engineer,  after  showing  the  party  his  room,  led  the 


A  FTTBNACE  BOOM  AT  SEA. 


THE    ENGINE    KOOM.  ^        .  J  J     , 

way  onward  through  the  passage-way 'between  the  ,state- 
rooms  to  a  winding  iron  staircase,  ,wtucii  led'  aojw^ior. 
much  more  convenient  way  than  that  afforded  by  the  step- 
ladder  already  referred  to.  It  would  be  impossible  to  con- 
vey, by  description,  any  adequate  idea  of  the  bewildering 
maze  of  mechanism  which  presented  itself  to  view  on  all 
sides  as  the  party  descended  to  the  several  successive 
floors.  They  went  down  flight  after  flight  of  iron  stair- 
way, and  walked  around  in  galleries  consisting  of  floors  of 
iron  open-work,  and  bordered  by  iron  balustrades.  The 
machinery  was  so  massive  and  ponderous,  and  all  its  move- 
ments were  so  deliberate  and  grand,  as  to  give  the  observer 
the  idea  of  resistless  force,  while  yet  every  thing  moved 
with  a  smoothness  and  gentleness  denoting  the  utmost' 
delicacy  of  finish  in  the  mechanism.  The  jar  which  is  felt 
in  the  motion  of  side-wheel  steamers  is  due,  not  to  any 
thing  like  jolting  in  the  machinery,  but  to  the  floats  of  the 
paddle-wheels  striking  the  water  with  such  great  force  and 
in  such  rapid  succession. 

At  length  the  party  reached  the  lower  floor,  where  the 
boilers  and  furnaces  were.  There  were  ten  of  these  fur- 
naces in  each  row,  making  forty  in  all !  On  the  iron  floors 
in  front  of  them  were  heaps  of  coal  which  the  men  were 
incessantly  shoveling  into  the  mouths  of  the  furnaces, 
which  mouths  looked  like  so  many  fiery  ovens  whenever 
the  men  opened  the  iron  doors  to  shovel  in  more  coal. 
The  men  were  very  thinly  clad ;  some  of  them  seemed  al- 
most half  naked.  Of  course  the  work  which  they  had  to 
perform,  notwithstanding  every  thing  that  could  be  done 
to  promote  ventilation,  subjected  them  to  the  endurance 
of  great  heat. 

"You  see  what  they  are  doing,"  said  Lawrence.  "They 
are  delivering  carbon  and  hydrogen  to  oxygen  to  be  de- 
voured." 


102,  ENORMOUS    FORCE. 

Lawrence  had*  to  draw  very  near  to  the  boys,  and  to 
fspea&  quite  loud,"  on  Account  of  the  roar  of  the  furnaces 
and  the  other  sounds  which  filled  the  air. 

The  men  who  had  charge  of  the  furnaces  were  incessant- 
ly at  work  opening  the  doors  and  shoveling  in  fresh  coal, 
and  seemed  to  be  urging  the  fires  to  the  highest  possible 
intensity.  The  fires  burned  very  fiercely,  too,  as  if  blown 
by  some  invisible  bellows — as  they  were,  in  fact — the  com- 
bustion being  urged  to  the  utmost  by  the  strong  current 
of  air  produced  by  the  draft  in  the  two  immense  chimneys. 

After  remaining  in  the  furnace-rooms  a  few  minutes,  the 
party  set  out  on  their  return,  and,  as  they  ascended  the 
several  staircases  and  walked  along  the  galleries  of  the 
several  stories,  the  engineer  pointed  out  to  them  the  most 
remarkable  and  conspicuous  parts  of  the  engine.  They 
were  particularly  struck  with  the  magnitude  of  the  cylin- 
ders, and  the  prodigious  force  with  which  the  piston-rods 
were  alternately  forced  up  and  then  down  into  them  again. 

The  cylinder,  as  probably  most  of  my  readers  know,  is 
the  heart,  as  it  were,  of  the  steam-engine,  being,  in  respect 
to  the  action  of  the  mechanism,  the  central,  and,  in  some 
respects,  the  most  essential  element  of  it ;  for  it  is  within 
the  cylinder  that  the  great  force  of  the  steam  is  exerted, 
and  its  great  work  done  in  driving  first  up  and  then  down 
the  piston  which  plays  to  and  fro  in  the  interior  of  it.  The 
cylinders  in  the  Scotia,  the  engineer  said,  were  one  hundred 
inches  in  diameter,  and  twelve  feet  stroke.  If  you  measure 
off  upon  the  floor  a  length  of  one  hundred  inches — that  is, 
about  eight  feet  and  a  half — which  you  can  do  accurately 
enough  by  taking  about  four  or  five  ordinary  steps,  and 
then  imagine  an  immense  iron  hogshead  with  straight 
sides  to  stand  on  a  bottom  of  that  diameter,  and  to  rise  to 
twice  the  height  of  a  tall  man's  head,  you  will  obtain  a 
pretty  just  idea  of  the  size  of  one  of  these  cylinders.  If 


TALK    WITH    THE    ENGINEER.  103 

then  you  imagine  that  there  are  two  of  them  in  the  Scotia's 
machinery,  and  that  such  a  volume  of  steam  must  pour  into 
them  from  the  boilers  that  each  may  be  filled  and  emptied 
as  often  as  once  in  a  second,  you  can  easily  understand 
with  what  enormous  rapidity  the  steam  must  be  genera- 
ted, and  will  be  less  surprised  at  its  requiring  forty  fur- 
naces to  produce  it. 

At  length  our  party  came  out  upon  the  deck  again. 
Lawrence  gave  the  engineer  a  generous  fee  for  the  benefit 
of  the  men  in  his  employ  among  the  machinery  and  at  the 
furnace  below.  The  engineer  invited  them  to  go  again  into 
his  state-room,  and  then,  sitting  on  the  little  sofa,  they  had 
ten  or  fifteen  minutes'  conversation  with  him  about  the  en- 
gine and  about  other  subjects. 

Lawrence  informed  him  that  he  had  read  somewhere 
that,  notwithstanding  the  high  degree  of  perfection  to 
which  machinists  had  attained,  in  modern  times,  in  the 
construction  of  engines,  it  was,  after  all,  only  about  one 
tenth  of  the  actual  power  developed  by  the  combustion  of 
the  coal  used  that  was  really  made  available  for  useful 
work  in  the  best  engines,  and  he  asked  him  whether  that 
accorded  with  his  ideas  and  experience. 

"Well,"  replied  the  engineer,  "I  should  think  that  that 
might  be  about  the  way  they  would  put  it  in  the  books. 
There  is  a  great  deal  of  waste.  There  is  a  great  part  of 
the  coal  that  goes  off  up  the  chimney  in  smoke  without 
being  burned  at  all.  Then  we  have  to  heat  up  such  a 
great  quantity  of  air  to  make  a  draft.  Then  a  great  deal 
of  heat .  escapes  from  the  boilers  and  the  machinery  out 
through  the  sides  of  the  ship  into  the  water,  and  from  the 
p moke-pipes  into  the  air.  It  is  not  a  large  portion,  after 
all,  of  the  heat  which  the  coal  produces,  or  might  produce, 
that  we  get  the  benefit  of  in  making  steam." 

The  engineer  did  not  confine  his  conversation  to  the  sub- 


104  ENORMOUS    FORCE. 

ject  of  the  engine  during  the  time  that  the  party  remained 
in  his  state-room,  but  told  them  about  Scotland,  where  he 
lived,  so  far  as  one  who  spends  most  of  his  life  in  sailing  to 
and  fro  across  the  Atlantic  can  be  said  to  live  any  where 
on  land.  He  related  to  them  several  anecdotes  illustrative 
of  Scotch  ideas  and  manners,  especially  those  of  the  coun- 
try people,  who  lived  in  lonely  districts  among  the  High- 
land glens.  He  told  of  one  aged  Scotch  woman,  who  at- 
tached great  value  to  a  knowledge  of  the  art  of  spinning 
linen  thread  by  means  of  a  distaff  and  spindle,  as  practiced 
when  she  was  a  child,  before  steam  and  machinery  had 
suspended  these  primitive  modes  of  labor.  "There,  are  a 
great  mony  puir  bargains  for  the  yoong  men  noo-a-days  in 
respect  of  lassies,"  she  said,  "  for  there  are  noombers  of 
them  flaunting  aboot,  and  thinking  themsels  very  bonnie, 
and  but  dinna  ken  how  to  dhraw  a  thread." 

At  length  Lawrence  and  the  boys  bade  the  engineer 
good-by  and  took  their  leave.  It  was  now  nearly  time  for 
the  luncheon-bell  to  be  rung,  for  Lawrence  found,  by  look- 
ing at  his  watch,  that  it  was  half  past  eleven,  and  twelve 
o'clock,  which  was  the  hour  for  luncheon,  comes  very  close 
upon  half  past  eleven  on  board  so  swift  a  steamer  as  the 
Scotia  when  she  is  sailing  toward  the  east  to  meet  the  sun. 
As,  however,  the  boys  passed  the  place  where  they  could 
look  down  through  the  great  opening  through  the  deck  to 
the  engine-room,  they  stopped  a  moment  to  look  once  more 
at  the  massive  and  ponderous  machinery,  and  to  observe 
the  wonderful  force  with  which  the  immense  iron  beams 
on  each  side  rose  and  fell  in  turning  the  crank  upon  the 
shaft  which  carried  the  paddle-wheels. 

"  I  see,"  said  Flippy ;  "  these  great  bars  coming  up  and 
down  turn  the  crank  and  work  the  paddle-wheels  in  the 
water  just  as  I  would  turn  a  grindstone  by  the  handle." 

"  Exactly,"  said  Lawrence ;  "  only  there  is  a  slight  dif- 


COAL   CONSUMED.  105 

ference  in  the  degree  of  power.  You  would  turn  the  grind- 
stone by  a  one-boy  power,  whereas  the  engines  carry  around 
this  shaft  with  a  five  thousand  horse  power." 

"  A  five  thousand  horse  power !"  exclaimed  John. 

"  So  the  engineer  told  me,"  said  Lawrence.  "  He  said 
that  that  was  the  force  indicated.  He  meant  by  that,  I 
suppose,  that  that  was  the  amount  of  force  which  it  was 
necessary  to  develop  in  the  steam.  Only  a  portion  of  it, 
however,  can  be  really  made  available  in  the  propulsion  of 
the  ship." 

"  What  a  big  team  five  thousand  horses  would  make  L" 
said  Flippy." 

"  It  would  indeed,"  replied  Lawrence.  "  Few  people  have 
any  idea  of  the  immensity  of  the  force  which  it  is  necessary 
to  develop  in  working  one  of  these  ships.  These  engines, 
as  the  engineer  said, '  indicate,'  as  they  term  it,  five  thou- 
sand horse  power ;  and  that  number  of  horses,  if  placed 
tandem,  would  make  a  line  eight  miles  long,  allowing  eight 
feet  in  length  for  each  horse  and  harness.  Of  course  it 
would  be  impossible  to  combine  the  strength  of  so  many 
horses  in  any  way,  least  of  all  in  harnessing  them  tandem. 
But  if  they  were  placed  four  abreast  it  would  make  a  team 
two  miles  long,  so  that  we  are  being  impelled  through  the 
water  by  all  that  can  be  used  of  a  force  equal  to  a  team 
two  miles  long  and  four  horses  abreast.  And  all  that  force 
is  developed  by  the  intensity  of  the  action  of  the  oxygen 
combining  with  the  carbon  and  hydrogen  in  the  coal.  The 
oxygen  devours  the  coal  at  the  rate  of  more  than  a  hun- 
dred tons  per  day !  five  times  as  much  every  day  as  is  re- 
quired by  many  a  family  in  New  York  for  their  whole 
winter's  supply. 

"  And  what  is  most  curious  about  it,"  said  Lawrence, 
"  and  almost  inconceivable,  is  that  this  force — as  much  as 
would  be  exerted  by  five  thousand  horses — is  only  about 

E2 


106  ENOKMOUS    FORCE. 

one  tenth  part  of  the  force  which  the  amount  of  coal  which 
they  burn  really  contains,  inasmuch  as  nine  tenths  of  it  is 
wasted,  or  employed  in  producing  the  draft ;  so  that  the 
force  which  they  really  deal  with,  it  would  seem,  is  that 
of *  fifty  thousand  horses  /" 

"  What  an  enormous  quantity  of  coal  they  must  have  on 
board,"  said  John,  "  to  use  one  hundred  tons  a  day !" 

"  They  fill  the  bunkers  up  every  voyage,"  said  Lawrence, 
"  and  the  bunkers  hold  eighteen  hundred  tons.  So  you  see 
what  an  enormous  weight  they  have  to  carry." 

"  And  then,"  continued  Lawrence, "  that  is  not  all.  There 
is  something  else  that  they  require  for  the  voyage  that 
amounts  to  a  great  deal  more,  in  respect  to  weight,  than 
even  the  coal." 

"What  is  it?"  asked  John. 

"  Guess,"  said  Lawrence. 

"  The  provisions,"  said  John. 

"  No,"  replied  Lawrence ;  "  the  provisions  would  not 
probably  weigh  more  than  a  tenth  part  the  weight  of  the 
coal." 

"The  ballast,"  said  Flippy. 

"  No,"  replied  Lawrence,  "  not  the  ballast.  Something 
even  more  important  than  that." 

"  Then  I  give  it  up,"  said  Flippy. 

"  It  is  something  of  the  greatest  possible  importance," 
said  Lawrence.  "  Without  it  we  could  not  get  along  at 
all.  And  there  is  a  great  deal  more  of  it  in  weight  to  be 
taken  on  board,  infinitely  more  in  bulk,  than  there  is  of 
coal." 

"  What  is  it  ?"  asked  John. 

"  The  oxygen,"  said  Lawrence. 


TONS    OF    AIR.  107 


CHAPTER  X. 

TEACKS    OF   THE    STEAMERS. 

BOTH  John  and  Flippy  were  very  much  surprised,  as 
perhaps  some  of  my  readers  will  be,  to  learn  that  the 
amount  of  air  necessary  to  contain  the  quantity  of  oxygen 
that  is  required  for  the  combustion  of  the  coal  in  the  fur- 
nace of  a  sea-going  steamer — and  it  is  the  same,  moreover, 
with  any  common  fire — so  far  exceeds  in  weight  the  fuel 
that  is  burned.  They  will,  perhaps,  be  still  more  surprised 
to  learn  how  enormous  the  excess  is.  The  most  careful 
experiments  have  been  made  to  determine  the  ratio,  and 
it  is  found  that  no  less  than  seventy-two  tons  of  air  are  re- 
quired for  every  ton  of  coal,  to  eifect  the  complete  com' 
bustion  of  it ! 

When  Lawrence  stated  this  to  the  boys  in  conversing 
on  the  subject  some  days  after  they  went  below  to  see  the 
engines,  they  could  hardly  believe  it.  John  said  he  did 
not  see  how  it  could  be. 

"I  can  not  positively  prove  it  to  you,"  replied  Law- 
rence, "  but  I  can  make  some  computations  with  you  some 
day  to  show  you  how  it  can  very  possibly  be.  As  for  the 
actual  fact,  we  have  to  take  the  testimony  of  the  scientific 
men  who  have  made  the  experiments ;  but  the  calculations 
which  I  can  make  with  you  will  show  that  something  like 
that  quantity  must  be  necessary,  and  so  will  make  the  re- 
sult of  the  experiments  not  improbable." 

John  said  that  he  should  like  to  see  the  computation. 
As  for  Flippy,  he  asked  whether  computation  was  any 
thing  like  arithmetic.  Lawrence  replied  that  it  was  a 


108  TRACKS    OP   THE    STEAMERS. 

kind  of  arithmetic.  Flippy  then  said  that  he  did  not  care 
about  it.  He  said  he  did  not  think  it  was  of  any  conse- 
quence how  much  air  it  took,  since  they  found  a  plenty  of 
it  all  along  the  way,  and  they  could  have  as  much  of  it  as 
they  pleased  without  its  costing  any  thing. 

"It  seems,  however,  on  the  contrary,"  said  Lawrence, 
"that  it  does  cost  them  a  great  deal,  for  a  large  part  of  the 
coal  which  they  burn  is  employed  in  heating  up  the  air  in 
the  chimneys,  as  the  engineer  said,  to  make  a  draft,  as  a 
means  of  bringing  the  air  into  the  ship  and  into  the  fur- 
naces." 

This  is  true,  and  it  is  a  very  important  thing  to  be  un- 
derstood. The  attention  of  visitors  to  such  ships,  and  also 
of  the  passengers  on  the  voyage,  is  often  drawn  to  the  cu- 
rious shapes  of  the  ventilators  and  wind-sails  which  are 
seen  here  and  there  rising  up  out  of  the  deck.  The  venti- 
lators are  made  of  copper,  and  are  of  the  form  of  immense 
speaking-trumpets,  with  mouths  as  large  as  the  open  end 
of  a  hogshead,  turned  always  toward  the  wind,  whichever 
way  it  blows.  The'  wind-sails,  though  made  of  sail-cloth, 
have  a  somewhat  similar  form.  The  lower  parts  consist 
of  long  cloth  tubes,  as  large  round  as  a  barrel,  and  extend- 
ing through  openings  in  the  deck  down  to  the  lower  re- 
gions of  the  hold.  At  the  upper  end  of  each  of  these  con- 
trivances, which  usually  reaches  high  above  the  deck,  there 
is  a  wide  opening  on  one  side,  which  is  always  turned  to- 
ward the  wind.  This  opening  has  two  wings,  one  on  each 
side,  which  are  drawn  out  and  fastened  by  cords  attached 
to  some  part  of  the  neighboring  rigging.  They  look,  on 
moonlight  nights,  like  so  many  ghosts  having  their  arms 
stretched  out  and  tied,  while  they  are  struggling  furiously 
in  the  wind  to  get  free. 

These  ventilators  and  wind-sails — the  upper  portions  of 
which  are  seen  rising  into  the  air  at  different  places  along 


IMMENSE    CONSUMPTION.  109 

the  decks,  the  lower  portions  of  them  passing  down  through 
various  openings  to  the  regions  below — are  so  many  pipes 
for  the  conveyance  of  oxygen  to  the  furnaces,  to  maintain 
the  combustion  of  the  coal,  as  well  as  also  to  supply  what 
is  necessary  for  the  respiration  of  the  men ;  for  there  is  a 
process  very  analogous  to  combustion  going  on  all  the 
time  in  the  lungs  and  in  the  tissues  of  the  body,  in  men 
and  animals,  and  this  makes  it  necessary  that  a  supply  of 
oxygen  should  be  brought  in  for  the  breathing  of  the  men 
as  well  as  for  the  blast  of  the  furnaces.  It  is  only,  how- 
ever, a  very  small  portion  of  the  whole  amount  brought 
into  the  ships  that  is  required  for  the  men ;  almost  the 
whole  is  required  for  the  fires.  This  portion,  being  brought 
down  by  the  ventilators  into  the  furnace  -  rooms,  is  then 
drawn  into  the  mouths  of  the  furnaces  by  the  draft  in  the 
chimneys ;  and  if  seventy-two  tons  of  air  are  required  for 
every  ton  of  coal,  it  is  easy  to  see  how  enormous  a  quantity 
in  all  must  be  brought  in  every  day — no  less  than  eight  or 
ten  thousand  tons.  And  inasmuch  as  air  can  not  be  moved, 
any  more  than  any  thing  else,  without  a  force  to  move  it 
proportioned  to  the  weight  to  be  moved,  it  is  easy  to  see 
how  great  an  ascending  force  in  the  chimney  must  be  re- 
quired to  bring  this  amount  up  through  them,  and  how 
large  a  proportion  of  the  coal  that  is  burned  must  be  re- 
quired to  produce  heat  enough  to  furnish  it. 

Intelligent  and  thinking  people,  in  crossing  the  Atlantic 
in  one  of  these  steamers,  are  often  much  impressed  with 
the  fact  that  more  than  a  hundred  tons  of  coal  are  burned 
every  day,  as  an  indication  of  the  vast  scale  on  which  the 
force-developing  power  of  the  engines  act.  But  the  thought 
that  the  ship,  as  she  glides  along  on  her  way,  has  to  gather 
from  the  circumambient  air  and  draw  into  her  fires  eight 
or  ten  thousand  tons  of  air  to  carry  on  the  combustion  of 
this  coal,  seems  to  be  really  more  impressive  still.  She 


110  TRACKS    OF    THE    STEAMERS. 

draws  it  in  as  air,  and  sends  it  out  again,  through  her 
chimneys,  a  confused  compound  of  carbonic  acid,  water, 
deoxydized  nitrogen,  and  unconsumed  hydrogen  and  car- 
bon, leaving  a  long  train  of  these  mingled  elements,  or  of 
such  of  them  as  are  visible,  in  the  air  to  mark  her  track. 

There  is  another  track  which  she  leaves  to  mark  (though 
not  visibly)  her  way,  and  that  is  a  line  of  slightly-warmed 
water  in  the  sea.  There  is  an  enormous  quantity  of  waste 
heat,  in  spite  of  all  the  precautions  taken  by  the  machine- 
makers  and  the  engineers  to  save  it,  which  escapes  through 
the  iron  of  the  ship  into  the  water  that  bathes  her  sides. 
Thus  she  leaves  in  her  wake  a  line  of  warmed  water — but 
slightly  warmed,  it  is  true,  but  still  really  warmed — which, 
if  it  were  cognizable  by  the  senses,  would  indicate  her  path. 

Both  these  tracks,  it  is  true,  are  very  evanescent.  The 
winds  soon  dissipate  the  one  left  in  the  air,  though  it  re- 
mains visible  sometimes,  in  the  long  line  of  smoke,  much 
more  persistently  than  we  should  expect,  while  the  waves 
and  currents  soon  obliterate  the  traces  of  the  warmth  left 
in  the  water.  But,  evanescent  as  this  latter  trace  is,  a 
very  large  fraction  of  the  heat  developed  by  the  combus- 
tion of  the  coal  in  the  furnaces  is  wasted  in  making  it.  In 
other  words,  the  company  expends  a  very  considerable 
portion  of  its  annual  outlay  in  warming  up  the  sea. 

Besides  these  two  very  evanescent  tracks  made  by  the 
ocean  steamers,  there  is  another  quite  permanent  one, 
though  to  us  invisible,  that  they  are  making  on  the  bed 
of  the  ocean  by  the  deposit  of  the  cinders  and  the  ashes 
thrown  overboard  as  refuse  from  the  fires.  All  the  steam- 
ers from  America  to  England  pursue  substantially  the 
same  track.  The  space  which  these  tracks  cover  is,  it  is 
true,  pretty  wide  in  mid-ocean,  as  the  ships  take  more 
northerly  or  more  southerly  courses  according  to  the  sea- 
son, or  to  the  probability  of  encountering  ice,  or  from  other 


THE    REFUSE.  Ill 

considerations.  This  deviation,  however,  is  not  very  great ; 
and  inasmuch  as  steamers  are  continually  passing  over  this 
space,  each  of  which  throws  overboard  many  tons  of  this 
black  refuse  every  day,  and  have  been  doing  so  now  for 
more  than  a  quarter  of  a  century,  the  general  course  which 
they  have  taken  must  be  marked  on  the  bottom  with  a 
dark  deposit  like  a  broad  black  road.  If  this  deposit  should 
be  mingled  as  it  falls,  and  partially  covered  after  it  has 
fallen,  with  the  general  sediment  of  the  sea,  proceeding 
from  the  turbid  flow  of  the  rivers  into  it,  and  if,  moreover, 
the  process  should  go  on  as  it  is  going  on  now  for  five  hun- 
dred or  a  thousand  years  more,  then  strata  of  rock  of  very 
considerable  thickness  would  be  formed,  tinged  with  black 
throughout  the  whole  extent  of  them  by  the  presence  of 
this  mass  of  ash  and  unconsumed  carbon. 

And  then,  if  at  some  future  age  of  the  world  this  sub- 
aqueous formation  should  be  upheaved  by  the  action  of 
these  vast  geological  forces  by  which  such  upheavals  have 
been  effected  in  former  times,  and  new  continents  should 
be  thus  formed,  these  strata  would  come  into  view,  and 
might  be  quarried,  and  the  blocks  used  in  the  construction 
of  buildings,  and  the  geologists  of  those  days  might  won- 
der how  such  a  rock  could  have  been  formed,  and  whence 
the  carbon  it  contained  could  have  been  derived. 

It  is  indeed  true  that  the  quantity  of  ashes  and  cinders 
thus  thrown  over,  though  absolutely  very  great,  is  in  each 
ejection  relatively  very  small  compared  with  the  immense 
extent  of  a  roadway  fifty  or  one  hundred  miles  wide  and 
three  thousand  miles  long ;  but  then,  on  the  other  hand,  a 
thousand  years  is  a  long  time,  and  there  is  no  special  reason 
for  not  supposing  that  the  process  may  go  on  for  even  a 
longer  period  than  that ;  and  as  at  every  discharge  of  these 
substances  from  the  ship  the  operation  occupies  perhaps 
half  an  hour,  during  which  time  the  ship  has  passed  over 


112  TRACKS    OF    THE    STEAMEKS. 

a  stretch  of  five  or  ten  miles,  the  whole  amount  must  be 
pretty  evenly  distributed. 

The  question,  however,  of  the  strata  of  rock  thus  formed, 
when  finally  upheaved,  being  tinged  with  black,  would  de- 
pend upon  whether  the  carbon  remained  in  the  formation, 
as  coal,  unchanged,  or  whether,  through  the  effect  of  chem- 
ical action,  it  was  changed  into  some  other  form.  The  dia- 
mond consists  of  carbon  in  a  crystallized  form.  Under 
what  conditions  the  crystallization  takes  place  is  not 
known ;  nor  do  we  know  at  all  to  what  conditions  such  a 
deposit  of  carbonaceous  material  would  be  subjected  at 
such  a  depth,  and  for  so  long  a  period.  We  at  any  rate 
know  nothing  to  exclude  the  supposition  that  portions  of 
it  might  become  crystallized,  and  thus  the  refuse  coal  re- 
jected from  the  ships  employed  to  take  fashionable  ladies 
across  the  Atlantic  at  our  age  of  the  world,  be  employed, 
in  the  mysterious  laboratory  of  nature,  in  forming  the  dia- 
monds for  the  fashionable  ladies  of  a  distant  future  age. 
The  transformation  would  not  be,  in  fact,  half  as  wonderful, 
nor,  when  considered  beforehand,  nearly  as  improbable  as 
the  formation  of  a  strawberry  out  of  juices  drawn  from  the 
ground  by  means  of  chemical  and  physiological  arrange- 
ments concealed  in  a  slender  stem  six  inches  long. 

But  these  are  all  mere  speculations — idle  speculations — 
some  might  say.  But  Lawrence,  in  discussing  them  with 
the  boys,  did  not  consider  them  as  really  idle,  since  the 
boys  were  much  interested  in  the  consideration  of  them, 
and  such  conversations  accustomed  them  to  the  carrying 
of  their  thoughts  beyond  the  region  of  the  senses,  to  the 
contemplation  of  phenomena  and  powers  in  the  great  realm 
of  nature  which  the  senses  can  not  bring  to  our  cogni- 
zance. 

Even  Flippy  was  beginning  to  be  considerably  interest- 
ed in  the  explanations  which  Lawrence  gave  him  of  the 


AJS    ENGINEER  AT  HIS   POST. 


MRS.  GRAY.  115 

hidden  workings  of  the  various  processes  and  changes  con- 
nected with  the  combustion  of  carbon,  and  he  had  a  de- 
sire, as  children  always  have  when  they  find  out  any  thing 
new,  to  tell  what  he  had  learned  to  some  one  else.  He  at- 
tempted to  explain  to  his  mother  something  which  he  had 
learned,  and  which  seemed  to  him  very  curious,  about  the 
working  of  the  engine,  but  she  did  not  take  any  interest 
in  hearing  what  he  had  to  say. 

"  Oh,  I  know  all  about  it,"  she  said.  "  I  have  been  down 
myself — part  way.  Some  people  were  going  down,  and 
they  asked  me  to  go  with  them.  But  I  was  satisfied  very 
soon.  It  is  an  awful  place.  I  did  not  go  more  than  half 
way  down.  But  then  I  went  far  enough  to  see  the  whole 
of  the  machinery,  and  I  understand  all  about  it — the  cyl- 
inder, and  the  steam-pipe,  and  things.  I  have  seen  them 
all,  and  I  know  all  about  it." 

Mrs.  Gray  did  not  seem  to  be  aware  that  there  is  a  great 
deal  that  the  mind  can  know  about  any  thing  that  is  re- 
markable that  lies  entirely  beyond  what  the  eye  can  see. 


116  WHAT   IS  SMOKE? 


CHAPTER  XL 

WHAT    IS     SMOKE? 

COMBUSTION,  contrary  to  what  young  persons  might  in 
general  suppose,  is  a  very  exact  process.  Oxygen  can  com- 
bine with  carbon  or  hydrogen  only  in  certain  precise  and 
definite  proportions.  In  making  the  combination  it  will 
give  out  just  so  much  heat.  It  can  not  be  prevented  from 
giving  out  the  full  amount,  nor  can  it  in  any  way  be  made 
to  give  out  more.  And  that  amount  of  heat  can  be  made 
to  afford  just  so  much  and  no  more  power  for  driving  an 
engine,  or  doing  any  other  useful  work. 

If  there  is  an  excess  of  carbon  in  the  furnace,  none  of  the 
excess  will  be  burned.  The  oxygen  that  is  admitted  will 
not  combine  partially  with  the  whole  amount,  but  will 
combine  perfectly  with  a  part  of  it — just  the  quantity  that 
it  requires — and  will  not  touch  the  rest  at  all,  but  will 
leave  it  in  the  form  of  cinders  in  the  fire,  or  allow  it  to  be 
carried  off  in  minute  black  flakes  up  the  chimney  as  smoke. 
If  there  is  more  than  the  proper  proportion  of  oxygen, 
only  the  proper  proportion  will  be  combined  with  carbon, 
and  the  rest  will  go  up  the  chimney  free  and  uncombined. 

Thus  the  union  of  oxygen  and  carbon  is  governed  by  a 
law  very  different  from  that  observed  in  the  case  of  the 
solution  of  sugar  or  salt  in  water.  In  a  glass  of  water  you 
can  put  any  quantity  whatever  of  sugar  or  salt — as  much 
or  as  little  as  you  please,  up  to  a  certain  amount — and  it 
will  all  be  dissolved,  and  will  be  diffused  equally  through- 
out the  whole  mass  of  the  water,  and  in  a  certain  way  will 
be  closely  united  with  it.  But  this  kind  of  union  is  not 


CHEMICAL   COMBINATION.  117 

chemical  union.  Chemical  union  is  considered  to  be  a  very 
much  more  intimate  union  than  this,  and  always  takes 
place  in  precise  and  definite  proportions — just  so  much  of 
one  substance  to  just  so  much  of  another — any  surplus  of 
either  substance  being  left  entirely  unchanged. 

To  our  senses  the  union  between  the  salt  or  the  sugar 
and  the  water  seems  as  intimate  as  possible,  but  the  differ- 
ence between  such  unions  and  that  of  chemical  combina- 
tion is  very  evident  in  the  results,  inasmuch  as  in  the 
former  case  the  nature  of  the  substances  is  not  changed. 
The  sugar,  for  example,  remains  sugar,  and  the  water  re- 
mains water  after  they  are  united  as  before.  You  can 
taste  them  both.  The  particles,  no  doubt,  lie  side  by  side 
in  the  mixture  unchanged,  as  poppy-seeds  and  grains  of 
gunpowder  of  the  same  size  would,  if  intimately  mingled. 
The  particles  of  sugar,  or  salt,  and  water  are  infinitely 
smaller  than  the  seeds  or  grains,  so  that  our  senses,  on  the 
closest  examination,  can  not  discern  them ;  but,  when  min- 
gled in  the  solutions,  they  remain  unchanged.  In  the  case 
of  lye,  on  the  other  hand,  which  consists  of  potash  dissolved 
in  water,  and  any  oily  substances  mingled  with  it  at  a  boil- 
ing heat,  the  result  is  that  a  soap  is  produced,  which  is  not 
a  mixture  of  oil  and  potash,  but  a  substance  entirely  differ- 
ent from  either,  and  having  entirely  different  properties. 

So,  if  you  put  a  little  whiting  into  a  cup  and  pour  water 
over  it,  you  will  have  merely  a  mixture  of  whiting  and 
water ;  neither  will  be  changed.  The  whiting  will  remain 
whiting,  and  the  water  water,  though  never  so  intimately 
mingled.  But  if,  instead  of  water,  you  pour  vinegar  upon 
the  whiting,  you  will  have  a  different  result.  Instead  of 
having  whiting  and  vinegar  in  the  mixture,  you  will  have 
new  substances  formed,  entirely  different  in  their  nature 
and  properties  from  either  of  those  that  you  put  in.  One 
of  these  new  substances  will  be  a  gas,  which  will  pass  off  in 


118  WHAT   IS    SMOKE? 

bubbles  into  the  air,  and  what  remains  in  the  cup  will  be 
something  entirely  new.  There  will  not  be  a  particle  of 
whiting  or  of  vinegar  there,  provided,  of  course,  the  two 
substances  were  mingled  in  the  right  proportion,  so  that 
the  whole  of  each  had  the  proper  quantity  of  the  other  at 
hand  to  combine  with  it. 

It  is  true  that  the  elements  of  the  substances  brought  to- 
gether will  remain  in  the  products,  but  they  will  be  formed 
into  new  combinations,  so  that  the  old  substances  will  en- 
tirely disappear,  and  new  ones,  sometimes  of  an  entirely 
opposite  character,  and  of  opposite  properties,  will  take 
their  place — that  is,  provided  that  the  union  is  a  chemical 
union. 

Now  combustion  is  a  chemical  union.  The  wood,  or  the 
coal,  or  the  substance,  whatever  it  is,  that  is  burnt,  disap- 
pears entirely  as  wood  or  coal,  and  the  oxygen  disappears 
as  free  oxygen.  To  speak  in  a  more  strictly  scientific  man- 
ner, however,  I  should  say  that  the  carbon  and  hydrogen 
generally  contained  in  the  wood  or  coal  disappear  as  car- 
bon and  hydrogen ;  for  there  are  other  substances  con- 
tained in  the  wood  or  coal  with  which  the  oxygen  can  not 
combine  in  the  combustion,  and  these  remain  unchanged 
and  form  the  ashes.  The  reason  why  these  substances  can 
not  burn  is  because  they  have  been  burnt  already.  Or,  to 
speak  scientifically,  the  reason  why  they,  too,  as  well  as  the 
carbon  and  hydrogen,  can  not  combine  with  the  oxygen,  is 
because  they  are  substances  which  are  already  combined 
with  oxygen  in  the  exact  proportion  of  their  capacity  for 
it,  being  substances  which  were  taken  up  from  the  ground 
by  the  roots  of  the  plant.  Thus,  when  the  sun  separates 
the  carbon  and  the  hydrogen  from  the  oxygen  in  the  leaves, 
to  use  them  in  forming  the  tissues  of  the  plants,  a  portion 
of  these  earthy  substances  were  employed  with  them,  and 
remained,  forming  a  part  of  the  substance  of  the  wood  or 


THE    TWO    CHAKACTEEISTICS.  119 

the  coal.  Then,  when  the  time  of  combustion  came,  the 
oxygen  could  only  reunite  with  the  carbon  and  hydrogen 
which  had  been  separated  from  it,  while  these  earthy  sub- 
stances, being  already  oxydized  substances,  remained  un- 
changed. 

Thus  the  union  of  carbon  or  of  hydrogen  with  oxygen  in 
combustion  is  a  chemical  union,  and  is  marked  by  the  two 
essential  characteristics  of  such  union,  namely, 

1.  The  combination  is  in  definite  proportions.     A  certain 
quantity  of  oxygen  can  combine  with  a  certain  precise 
quantity  of  carbon,  no  less  and  no  more.     And, 

2.  The  result  of  the  union  is  the  production  of  new  sub- 
stances quite  different  in  their  nature  and  properties  from 
the  substances  combined. 

Lawrence,  when  he  had  finished  explaining  all  these 
things  to  the  boys,  said  to  them, 

"  And  now,  boys,  if  either  of  you  wish  to  remember  all 
this,  the  way  is  to  run  it  into  your  memory  through  the 
tips  of  your  fingers.  The  very  first  time  you  are  on  deck 
and  see  volumes  of  black  smoke  coming  out  of  the  chim- 
neys, say  to  yourself, '  Nearly  all  that  is  carbon,  in  very  fine 
particles,  which  could  not  find  oxygen  enough  to  combine 
with  it  in  the  fire ;  for  oxygen  can  only  take  up  a  certain 
amount,  so  much  and  no  more,  since  substances  can  com- 
bine chemically  only  in  precise  and  definite  proportions.' 

"  When  you  see  the  smoke  coming  out  in  that  way  the 
first  time,"  continued  Lawrence,  "  you  say  that  once,  and 
touch  one  finger.  When  you  see  it  the  next  time,  you  say 
it  again  upon  another  finger ;  and  by  the  time  that  you 
have  gone  over  the  fingers  of  both  hands,  and  perhaps 
even  of  one,  you  will  have  impressed  the  principle  upon 
your  mind  so  strongly  that  you  never  will  forget  it." 

"  But  I  could  not  remember  all  that,"  said  Flippy ;  "  I 
could  not  remember  half  of  it." 


120  WHAT    IS    SMOKE? 

"  Oh,  you  need  not  say  it  in  those  words,"  replied  Law- 
rence. "  You  can  make  up  any  words  you  please  to  ex- 
press the  idea." 

"  But  I  could  not  make  up  any  words  at  all,"  said  Flippy, 
"  to  say  such  a  thing." 

"  Neither  could  I,"  said  John. 

"  Try,"  said  Lawrence. 

So  John,  after  looking  up  intently  into  the  smoke  a  mo- 
ment, said,  speaking  in  a  somewhat  slow  and  hesitating 
manner,  as  if  thinking  what  to  say, 

"  Well,  all  that  black  smoke  is  made  up  of  little  parti- 
cles of  carbon  that  did  not  find  any  oxygen  to  seize  it. 
Does  the  oxygen  seize  the  carbon,  or  the  carbon  the  oxy- 
gen?" said  John,  interrupting  himself  to  ask  the  question. 

"  They  seize  each  other,"  replied  Lawrence ;  "  or,  at  any 
rate,  the  force  acts  between  them,  and  whether  it  resides 
any  more  in  one  than  in  the  other  we  can  not  say.  The 
truth  is,  we  have  no  very  clear  idea  of  what  force  is,  or 
in  what  it  consists,  when  we  attempt  to  form  a  conception 
of  it,  pure  and  simple.  We  pass  there  out  of  the  realm  of 
human  knowledge — at  least  we  pass  out  of  the  realm  of 
my  knowledge.  I'll  ask  the  major  about  it  some  day,  but 
I  don't  think  he  can  tell  me  any  thing  that  is  satisfactory. 
We  give  the  name  of  force  to  something  that  produces 
motion.  We  have  an  idea  of  motion,  but  none  of  the  force 
producing  it,  distinct  from  that  of  the  motion.  At  any 
rate,  I  don't  think  we  can  make  any  distinction  between 
two  substances  having  a  strong  affinity  for  each  other,  in 
respect  to  the  affinity  being  exercised  more  by  one  than 
the  other." 

"  Well,"  said  John,  "  then  I  will  say  they  are  particles 
of  carbon  that  did  not  find  any  oxygen  to  combine  with." 

"  Very  good,"  said  Lawrence. 

"  Because,"  continued  John,  encouraged  by  Lawrence's 


THE   PROCESS    IN   THE    CHIMNEY.  121 

commendation,  "  there  must  be  just  so  much  oxygen  for  so 
much  carbon,  and  if  there  is  any  excess  of  either  it  has  to 
go  up  the  chimney  just  as  it  is." 

"  That  is  all  right,"  said  Lawrence.  "  And  then  there  is 
a  large  quantity  of  the  other  substances  that  pass  through 
the  furnaces,  which  escape  up  the  chimney  uncombined. 
For  you  see  they  must  not  only  come  together  in  the  right 
proportions,  but  they  must  come  together  in  a  hot  enough 
place  for  them  to  combine.  There  might  be  a  little  stream 
of  flakes  of  carbon  coming  up  through  the  fire  in  one  place, 
and  a  stream  of  air  with  oxygen  in  it  in  another  place,  as 
we  often  see  happen  in  a  common  fire.  If  these  streams 
were  to  come  together  in  the  fire,  the  substances  would 
combine,  and  more  heat  would  be  developed.  But  if  they 
get  through  the  fire  without  mingling,  and  afterward  min- 
gle in  the  chimney  when  it  is  comparatively  cool,  they  will 
not  combine,  but  will  come  out  at  the  top  of  the  chimney 
in  the  smoke,  and  float  away  into  the  air  unchanged. 

"  The  amount  of  it  is,"  continued  Lawrence,  "  that  in  the 
furnace  of  a  steam-engine,  or  in  any  other  fire,  there  are 
four  chemical  substances  concerned,  only  three  of  which, 
however,  take  any  active  part.  These  three  are  carbon, 
hydrogen,  and  oxygen.  The  fourth,  which  takes  no  active 
part,  but  only  does  mischief  by  being  in  the  way  and  pre- 
venting the  others  from  acting,  is  nitrogen.  Of  the  three, 
the  carbon  and  oxygen,  so  far  as  they  come  together  in  the 
right  proportions,  and  in  hot  enough  places,  combine,  and 
form  carbonic  acid.  The  same  with  the  oxygen  and  hy- 
drogen, only  they  form  vapor  of  water.  All  the  carbon 
and  hydrogen  which  do  not  find  any  oxygen  to  combine 
with  them  in  the  actual  fire,  and  all  the  oxygen  that  does 
not  find  any  carbon  and  hydrogen,  go  up  the  chimney  to- 
gether, and  form  the  smoke.  But  all  that  part  of  the 
smoke  that  we  can  see  is  formed  of  minute  particles  of  the 

F 


122 


WHAT    IS    SMOKE? 


carbon  mixed  with  the  vapor  of  water,  for  all  the  other 
substances  are  transparent  gases,  entirely  invisible. 

"  It  is  a  great  deal  better  to  understand  all  this,"  added 

Lawrence,  "  for  then,  when  you  see  a  thick  smoke  coming 

up  from  a  chimney,  or  from  a  fire  in  the  woods,  or  from  a 

burning  building,  or  from  a  steamer's  smoke-pipe  on  a  river 

or  on  a  lake,  there  will  be  some  meaning 

in  it  to  your  eyes,  or,  rather,  to  your 

minds.     And  now,  Flippy,  try  and  see  if 


you  can  state  the  case.  You  can  do  it.  You  know  you 
got  the  prize  for  your  recapitulation." 

"  I  have  not  got  it  yet,"  said  Flippy. 

"  No ;  but  you  will  have  it  when  we  get  to  Liverpool," 
said  Lawrence.  "  Or,  if  you  are  afraid  I  may  forget  it,  or 
may  not  have  an  opportunity  to  give  it  to  you,  I'll  give 
you  the  money  now — enough  to  buy  a  compass  for  your- 
self—if you  prefer." 

"  How  much  should  you  give  me  ?"  asked  Flippy. 

Lawrence  hesitated  a  moment,  and  then  said,  "  A  shil- 
ling." 


A  SHILLING'S  WOKTH.  123 

"An  English  shilling  or  an  American  shilling?"  asked 
Flippy. 

"  An  English  shilling,"  replied  Lawrence. 

Flippy  hesitated  for  a  moment,  and  .then  said  he  would 
prefer  to  wait  and  let  Lawrence  buy  the  compass  himself. 
He  thought  that  if  he  waited  and  allowed  Lawrence  to  buy 
the  compass,  he  would  very  probably  get  one  that  would 
cost  more  than  a  shilling.  Flippy  did  not  evince  much 
delicacy  of  mind  in  looking  out  so  shrewdly  for  the  value 
of  the  prize  which  he  was  to  receive,  when  the  prize  was 
earned,  if  a  prize  in  such  a  case  can  be  said  to  be  earned  at 
all  by  his  merely  having  attended  well  to  certain  instruc- 
tion which  was  of  great  benefit  to  him  to  receive,  but  of 
no  benefit  at  all  to  Lawrence  to  impart.  But  delicacy  of 
mind  is  a  quality  that  is  developed  late  and  slowly  com- 
pared with  many  other  faculties,  in  all  children,  and  espe- 
cially in  such  boys  as  Flippy.  Flippy  had  a  great  many 
excellent  qualities,  but  he  had  not  yet  acquired  this.  Any 
one  would  have  evinced  great  ignorance  of  human  nature, 
and  of  the  order  in  which  the  different  moral  sentiments 
are  developed  in  the  minds  of  children,  to  have  expected 
it  of  him.  Lawrence  did  not  expect  it,  nor  was  he  at  all 
surprised  or  disappointed  in  not  finding  it  in  him.  In  a 
word,  he  knew  something  of  the  philosophy  of  mind  as 
well  as  of  the  philosophy  of  matter. 


124  THE  "FIDDLE/ 


CHAPTER  XII. 

THE  "FIDDLE." 

THERE  is  an  important  truth  in  the  sentiment  that  Law- 
rence expressed  to  the  boys  in  saying  that  the  knowledge 
of  the  philosophy  of  any  phenomenon  or  process  which 
takes  place  in  the  world  around  us  imparts  a  great  signifi- 
cance to  the  appearances  which  they  present  to  our  view, 
and  so  greatly  increases  the  interest  which  we  take  in 
them.  The  boys  had  an  illustration  of  this  the  next  time 
they  went  by  the  "fiddle,"  for  it  was  by  this  whimsical 
name  that  the  apparatus  for  hoisting  up  the  ashes  and  cin- 
ders, or  the  place  where  this  operation  was  performed,  was 
called.  Seamen  and  printers,  though  so  entirely  unlike  in 
many  respects,  are  very  much  alike  in  the  oddity  and  gro- 
tesqueness  of  the  names  they  fancy  for  any  thing  that  they 
have  to  name. 

When  John  and  Flippy  had  passed  by  the  fiddle  before, 
and  had  witnessed  the  hoisting  up  of  the  ashes  and  cinders, 
they  had  been  interested  in  it  only  as  a  mechanical  opera- 
tion. They  listened  to  the  rattling  of  the  machinery,  and 
to  the  change  in  the  sound  as  the  full  tubs  were  brought 
up  or  the  empty  ones  sent  down.  They  watched  the  long 
chain  as  it  came  up  from  the  deep  well,  thus  measuring 
the  depth,  which  seemed  wonderfully  great,  and  were  im- 
pressed with  the  strength  and  vigor  exhibited  by  the  men 
in  carrying  off  the  heavy  tubs  or  buckets  so  rapidly  to  the 
ship's  side,  and  emptying  the  black  and  smoking  contents 
through  the  shoot  into  the  sea. 

Now,  however,  after  Lawrence  had  explained  to  them 


ASHES    AND    CINDEKS.  125 

the  nature  and  character  of  the  cinders,  and  of  the  ashes 
mixed  with  them,  there  was  a  much  greater  significance  in 
the  operation  than  when  they  saw  it  before.  Their  thoughts 
descended  into  the  furnace  where  they  had  seen  the  firemen 
throw  in  the  coal  on  the  day  when  they  went  down  among 
the  machinery,  and  they  pictured  to  their  minds  the  furi- 
ous heat  developed  by  the  force  with  which  the  carbon 
united  with  the  oxygen  that  came  within  its  reach.  They 
saw  how,  in  the  immense  rush  and  turmoil  of  the  air  in 
passing  through  the  fire,  many  small  fragments  would  es- 
cape combustion,  and  would  get  covered  by  the  ashes  left 
from  the  portions  that  were  burnt,  and  then,  with  the  ashes, 
would  fall  down  through  the  bars  of  the  grate  to  the  ash- 
pit, where  the  heat  was  not  great  enough  for  any  stray  ox- 
ygen which  might  be  there  to  combine  with  them.  From 
the  ash-pit  they  saw  the  cinders  brought  up  hot  and  smok- 
ing, but  not  hot  enough  for  combustion  to  go  on,  in  the 
great  iron  buckets  to  the  deck,  and  then  cast  into  the  sea. 
They  followed  them  in  imagination  there  as  they  were 
spread  along  the  water  by  the  swift  advancing  motion  of 
the  ship,  and  sank  gradually  down,  the  heaviest  portions 
going  in  advance,  and  the  lighter  ones  following  more 
slowly.  They  pictured  in  their  minds,  too,  the  long  dark 
track  which  they  must  leave  on  the  bottom  of  the  sea,  and 
reflected  how  this  track  must  be  gradually  widened,  and 
extended,  and  made  continuous  by  the  repeated  voyages 
of  the  same  and  other  ships,  until,  in  the  course  of  centu- 
ries, the  whole  bottom  of  the  sea  in  the  line  of  their  course 
would  become  blackened  with  them. 

While  John  was  considering  these  things,  Flippy  sud- 
denly said, 

"  If  we  had  such  a  place  as  this  on  land,  what  a  grand 
thing  it  would  be  to  play  going  down  into  a  mine." 

"  Yes,"  said  John,  "  it  is  very  deep.     See  how  far  down 


126 

the  chain  goes !  They  let  you  down  into  real  coal  mines 
in  very  much  such  a  way  as  that.  You  get  into  a  mon- 
strous great  bucket  or  tub,  and  they  let  you  down  by  a 
windlass  and  chain." 

"TJiese  buckets  are  big  enough  for  me,"  said  Flippy.  "I 
mean  to  ask  the  men  to  let  me  down.  It  will  be  good  fun. 
I'll  play  that  I'm  going  down  into  a  mine." 

"  No,"  said  John,  seizing  Flippy  at  the  same  time  by  the 
arm  in  order  to  restrain  him,  "you  will  get  your  clothes 
all  covered  with  ashes  and  cinders." 

"  That's  nothing,"  said  Flippy ;  "  I  can  brush  them  clean 
in  a  minute  when  I  get  down.  Besides,  these  clothes  are 
only  old  ones  which  I  brought  to  wear  at  sea." 

"  No,"  said  John, "  you  must  not  go." 

"  I'll  stand  up  straight  exactly  in  the  middle  of  the  tub, 
and  not  touch  the  sides  at  all,"  said  Flippy.  : . 

"  No,"  said  John  again, "  you  must  not  do  it.     Besides, 
the  men  would  not  let  you  do  it." 
.     "  Let  me  just  ask  them,"  said  Flippy. 

As  he  had  been  pulling  all  this  time  to  free  himself  from 
John,  and  seemed  to  insist  so  strenuously  upon  his  deter- 
mination, absurd  and  preposterous  as  it  was,  John  now 
partially  released  his  hold,  being  confident,  moreover,  that 
if  Flippy  were  to  ask  the  men  he  would  be  at  once  refused. 
Flippy  accosted  one  of  the  men  at  the  chain  with, 

"  I  say,  let  me  down  into  the  hold  in  one  of  those  empty 
buckets." 

The  man  looked  at  him  a  moment  with  an  expression  of 
mingled  surprise  and  amusement  in  his  countenance,  and 
then  said, 

"All  right !  when  the  next  bucket  comes  up,  jump  in." 

But  John  immediately  took  hold  of  Flippy's  arm  again 
and  pulled  him  away,  saying  that  he  positively  must  not 
do  any  such  a  thing.  It  would  be  the  worst  kind  of  a  mis- 


GOING   DOWN    BY    A   TUB. 


A    PECCADILLO.  129 

demeanor,  he  said.    He  would  have  to  pay  at  least  a  double 
fine  for  it. 

So  Flippy  allowed  himself  to  be  drawn  reluctantly  away. 

"  I  think  even  your  asking  to  go  was  a  peccadillo,"  said 
John, "  and  that  you  ought  to  pay  a  two-cent  fine,  at  any 
rate." 

"  No,"  said  Flippy. 

"  I'll  leave  it  to  Lawrence,"  said  John. 

"I'd  just  as  lief  leave  it  to  him  as  not,"  said  Flippy. 

So  the  boys  went  together  to  find  Lawrence,  and  stated 
the  case  to  him. 

"  He  wanted  the  men,"  said  John, "  to  let  him  go  down 
into  the  hold  in  one  of  the  empty  buckets,  all  black  with 
ashes  and  cinders,  and  I  had  the  hardest  work  to  prevent 
him." 

"I  wanted  to  see  how  astonished  the  stokers  would 
look,"  said  Flippy, "  to  see  such  a  boy  as  me  coming  down 
among  them  in  that  way." 

Lawrence  paused  a  moment,  and  then  said  it  seemed  to 
him  that  was  rather  a  foolish  thing  to  do. 

"Not  a  bit  more  foolish  than  it  is  for  people  to  be  let 
down  into  a  real  mine  by  a  big  tub,  and  ropes,  and  chains, 
in  almost  exactly  the  same  way,"  said  Flippy. 

Lawrence,  who  had  himself  gone  through  with  that  ex- 
perience, rubbed  his  mustache  to  conceal  a  smile,  and  ad- 
mitted he  did  not  know  exactly  what  to  say  in  reply  to 
that  argument.  Still  he  must  consider,  he  said,  that  at- 
tempting to  do  such  a  thing  on  board  ship,  and  putting 
John  to  the  trouble  of  preventing  him,  was  a  peccadillo, 
and  that  he  must  be  fined  two  cents. 

"All  right!"  said  Flippy;  and  he  at  once  put  his  hand 
into  his  pocket,  and,  drawing  out  some  money,  paid  his  fine 
in  the  most  good-natured  manner  possible. 

"And  this  reminds  me,"  said  Lawrence,  "of  the  question 
F2 


130  THE  "FIDDLE." 

between  you  and  me,  John,  about  the  comparative  com- 
bustibility of  wood  and  iron.  We  have  never  settled  that 
question.  We  were  to  leave  it  to  the  major." 

It  was  agreed,  after  a  little  farther  conversation  on  the 
subject,  that  they  would  ask  the  major  to  hear  and  decide 
the  question  that  evening  after  tea.  They  told  Flippy 
that,  if  he  wished,  he  could  come  too.  He  said  he  thought 
it  was  very  foolish,  but  he  would  like  well  enough  to  hear 
what  they  had  to  say  about  it. 

Accordingly,  that  evening,  after  tea,  the  boys  took  the 
major  to  a  part  of  the  table  where  no  one  was  sitting,  and 
proposed  the  question  to  him.  But,  in  order  that  wrhat  he 
said  upon  the  subject  in  giving  his  decision  may  be  under- 
stood by  the  reader,!  must  make  one  explanation, which  is 
this :  that  all  substances  do  not  ignite^  as  it  is  called — that 
is,  take  fire — at  the  same  temperature.  In  other  words,  the 
degree  of  heat  at  wThich  oxygen  will  begin  to  combine  with 
another  substance,  with  that  intensity  of  action  and  that 
development  of  light  and  heat  which  constitutes  combus- 
tion, is  quite  different  in  different  substances. 

For  instance,  if  we  should  place  a  bit  of  phosphorus,  one 
of  sulphur,  and  one  of  coal,  all  of  the  same  size,  upon  a 
shovel,  over  a  hot  bed  of  coals,  and  if  the  iron  of  the  shovel 
were  of  equal  thickness  in  every  part,  and  the  heat  of  the 
coals  the  same  in  every  part,  so  that  the  three  combusti- 
bles should  all  be  gradually  heated  in  the  same  degree, 
they  would  begin  to  burn  at  very  different  times,  showing 
that  they  require  different  degrees  of  heat  to  commence 
the  process  of  combustion. 

The  phosphorus  would  begin  to  burn  first,  then  the  sul- 
phur, and  last  of  all  the  carbon. 

We  take  advantage  of  the  different  degrees  of  heat  thus 
required  in  the  construction  of  phosphoric  matches.  Phos- 
phorus requires  so  slight  a  degree  of  heat  to  ignite  it  that 


THE    POINT   OF    COMBUSTION.  131 

a  gentle  rubbing  is  sufficient.  When  we  rub  the  match — 
which  we  do  upon  something  that  is  a  little  rough,  in  order 
to  increase  the  friction — the  phosphorus  that  happens  to  be 
on  that  part  of  the  match  which  comes  in  contact  with  the 
rubbing  surface  is  heated,  so  that  it  begins  to  burn ;  that 
is,  it  is  heated  so  as  to  bring  it  within  the  power  of  the 
oxygen  floating  in  the  air  all  around  it  to  seize  and  com- 
bine with  it.  The  oxygen,  in  combining  with  it,  develops 
more  heat,  and  this  prepares  the  next  particles  of  phospho- 
rus to  be  devoured,  and  the  heat  which  they  develop  the 
next,  the  intensity  of  the  heat  increasing  all  the  time  as 
the  burning  advances.  This  heat  soon  brings  the  sulphur 
that  is  close  at  hand  up  to  the  point  of  combustion  for  sul- 
phur, and  this  second  combustion  develops  more  heat  still. 
But  some  little  time  elapses  before  the  heat  becomes  suffi- 
cient to  raise  the  carbon  of  the  wood  up  to  its  burning 
point,  which  is  a  good  deal  higher  than  that  of  sulphur. 
You  will  see  the  little  faint  blue  flame  of  the  sulphur  float- 
ing about  the  end  of  the  match  for  quite  a  little  time  be- 
fore the  heat  accumulates  sufficiently  to  bring  the  temper- 
ature of  the  wood  up  to  the  burning  point  of  the  carbon 
and  hydrogen  of  which  the  wood  is  composed. 

Now  the  fact  in  respect  to  iron  is,  that  it  has  a  strong 
affinity  for  oxygen,  and  will  combine  with  it,  either  in  a 
slow  and  gradual  manner,  at  the  common  temperature  of 
the  atmosphere,  or  in  a  very  violent  and  rapid  manner  by 
the  process  of  combustion;  but  it  requires  either  so  intense 
a  heat  when  the  supply  of  oxygen  is  limited,  or  such  an 
abundant  supply  of  oxygen  when  the  initial  heat  is  not 
very  great,  that  in  all  the  ordinary  exposures  to  heat  and 
oxygen  which  iron  undergoes  in  the  practical  purposes  of 
life,  it  is  perfectly  safe  from  taking  fire  at  all.  It  burns 
only  very  partially  even  in  the  great  heat  of  a  blacksmith's 
forge. 


132  BURNING    OF   IKOX. 


CHAPTER  XIII. 

BURNING     OF     IRON. 

As  soon  as  the  party  which  was  collected  to  hear  the 
major's  decision  of  the  question  in  respect  to  the  compara- 
tive combustibility  of  iron  and  wood  were  seated  in  the 
saloon — the  major  on  the  back  side  of  the  table,  under  one 
of  the  windows,  and  Lawrence  and  the  boys  on  the  front 
side,  facing  him — the  major  opened  the  business  by  asking, 

"  Well,  young  gentlemen,  what  is  the  question  now  ?" 

"  The  question  is,"  said  John,  "  which  is  most  combusti- 
ble, wood  or  iron." 

Now  the  major  was  very  quick  and  prompt  in  all  his 
actions,  as  military  men  are  apt  to  be,  but  he  was  also  very 
exact  and  precise.  Indeed,  the  habit  of  exactness  and  pre- 
cision, and  a  very  distinct  and  clear  apprehension  of  the 
points  to  be  considered  are  quite  necessary  as  a  means  of 
making  promptness  and  rapidity  of  action  safe. 

"Ah!"  said  the  major,  " that's  rather  a  nice  question." 
Then,  after  musing  a  moment,  he  repeated  the  words, 
"  Which  is  most  combustible  ?" 

"  Yes,"  replied  John ;  "  Lawrence  says  that  iron  is  the 
most  combustible,  and  I  say  that  wood  is." 

"  It  depends  upon  exactly  what  you  mean  by  combusti- 
ble," said  the  major.  "Were  you  talking  science,  or  was 
it  common  conversation?" 

"  It  was  common  conversation,"  replied  John ;  "  I  said  I 
was  glad  we  were  coming  in  an  iron  ship,  for  an  iron  ship 
could  not  burn.  But  Lawrence  said  that  iron  was  more 
combustible  than  wood." 


WHAT   IS    COMBUSTIBLE?  133 

"  More  strictly  and  completely,"  said  Lawrence. 

"  Did  he  say  strictly  and  completely  ?" 

"  Yes,  I  believe  he  did  say  something  like  that,"  replied 
John. 

"  That  makes  it  difficult  to  decide  the  question,"  said  the 
major.  "If  he  had  simply  said  in  common  conversation,  and 
talking  about  ships  at  sea,  that  iron  was  more  combustible 
than  wood,  so  as  to  give  the  idea  thai;  an  iron  ship  would 
be  more  easily  burned  than  a  wooden  one,  he  would  have 
been  wrong ;  for,  in  common  parlance,  iron  is  not  combus- 
tible at  all — that  is,  it  will  not  ignite  under  any  ordinary 
circumstances  in  respect  to  temperature  and  supply  of  ox- 
ygen. But  by  saying  strictly  and  completely,  he  qualified 
the  word  combustible,  and  gave  it  in  some  degree  a  scien- 
tific sense.  And  in  that  sense  he  was  right;  for  iron  will 
combine  with  oxygen  in  combustion  if  the  temperature  and 
the  supply  of  oxygen  is  right.  And  it  combines  complete- 
ly, for  every  particle  of  it  will  be  consumed.  If  there  is 
any  thing  in  the  mass  that  is  not  consumed,  it  must  be 
some  other  substance  accidentally  present,  and  forms  no 
part,  really,  of  the  iron. 

"  But  with  wood  it  is  different.  There  are  certain  earthy 
substances  in  wood  which  help  to  form  the  wood.  They 
are  thus  parts  of  the  wood.  But  they  will  not  burn,  for 
they  are  already  oxydized.  Thus  wood,  as  wood,  is  not 
wholly  combustible,  but  iron,  as  iron,  is. 

"  So,  in  a  scientific  point  of  view,  Lawrence  was  right ; 
but  in  respect  to  the  use  of  language  in  common  parlance, 
he  was  wrong.  And  as  I  may  consider  that  there  was 
some  little  doubt  in  which  light  the  words  ought  to  be  re- 
garded in  such  a  conversation  as  that,  I  shall  give  the  ben- 
efit of  the  doubt  to  the  youngest  party,  and  decide  the 
question  in  favor  of  John." 

The  major  was  always  very  ingenious  in  finding  grounds 


134  BURNING    OF    IRON. 

for  deciding  all  questions  in  favor  of  the  weaker  party.  He 
took  great  care,  however,  in  doing  this,  not  to  disguise  or 
confuse  in  any  way  the  truth  in  respect  to  any  principles 
that  were  involved  in  the  question. 

John  was,  of  course,  well  satisfied  with  the  major's  de- 
cision, but  Flippy  shook  his  head  and  looked  incredulous, 
and  said  that  he  never  thought  that  iron  was  combustible 
at  all,  and  he  could  hardly  believe  it  now.  The  major  said 
he  could  prove  it  to  him  if  he  had  a  file  and  a  piece  of 
wire,  or  any  other  piece  of  iron  that  he  could  file  so  as  to 
let  the  filings  fall  into  a  flame. 

"  The  reason,"  said  he, "  why  any  ordinary  piece  of  iron 
will  not  burn  in  a  common  fire  is  because  it  is  too  large  in 
proportion  to  the  heat  of  the  fire  and  the  supply  of  oxygen. 
If  we  make  the  particles  small  enough,  iron  will  burn  splen- 
didly in  the  flame  of  a  candle.  If  I  had  a  file  here  I  could 
show  you  in  a  moment." 

So  saying,  the  major  looked  about  him,  and  felt  in  his 
pockets  as  if  he  expected  to  find  such  a  thing  as  a  file  in 
an  elegant  gentleman's  pocket,  or  on  the  tables  of  a  gay 
and  splendid  saloon  of  an  Atlantic  steamer,  filled  with 
groups  of  ladies  and  gentlemen,  after  tea,  on  a  pleasant 
summer  evening. 

He  drew  from  his  pocket,  not  a  file,  but  a  handsome  knife 
of  several  blades. 

"  Perhaps  this  will  do,"  he  said.  He  took  from  another 
pocket  a  key,  and  then  drew  one  of  the  candles  which  was 
on  the  table  near  him,  and,  calling  the  boys  to  look,  he  be- 
gan scraping  the  key  with  the  back  of  the  large  blade  of 
the  knife,  holding  it,  while  he  did  so,  over  the  flame. 

The  portions  of  iron  which  were  thus  separated  from  the 
key  by  the  corner  edge  of  the  back  side  of  the  blade  were, 
of  course,  exceedingly  minute — so  minute  that  they  were 
entirely  invisible  until  they  fell  into  the  flame,  where,  in 


THE    SECEET    OF    GUNPOWDER.  135 

burning,  they  flashed  into  beautiful  scintillations,  very  del- 
icate and  fine,  it  is  true,  but  very  beautiful. 

"  They  burn  just  like  gunpowder,"  said  Flippy. 

"  They  burn  as  really  and  truly  as  gunpowder,"  said  the 
major,  "but  not  like  it.  The  burning  of  gunpowder  is  the 
combustion  of  sulphur  and  carbon." 

"  And  saltpetre,"  said  John. 

"No,"  replied  the  major.  "The  saltpetre  does  not  burn ; 
it  furnishes  the  oxygen  for  the  burning  of  the  other  two 
ingredients.  That's  the  secret  of  the  force  of  gunpowder. 
The  sulphur  and  the  carbon,  two  combustibles,  are  mixed 
intimately  with  a  substance  which  furnishes  oxygen  close 
at  hand,  and  so  they  burn  with  great  rapidity.  But  the 
flame  of  sulphur  and  carbon  is  very  different  from  that  of 
iron,  as  we  should  see  if  we  had  some  gunpowder  to  try." 

Flippy  said  that  they  must  have  gunpowder  on  board, 
for  they  always  fired  a  gun  on  leaving  and  entering  port, 
and  he  would  go  and  ask  one  of  the  waiters  to  get  him 
some.  He  was  about  starting  off  for  this  purpose,  but  the 
major  stopped  him,  saying  that,  although  such  pyrotechnics 
as  had  been  produced  by  iron  scrapings  from  a  key  into  the 
flame  of  a  candle  might  be  allowable,  an  attempt  to  play 
off  fireworks  with  gunpowder  in  such  a  saloon,  in  the  mid- 
dle of  the  Atlantic,  might  be  thought  rather  out  of  place. 
So  he  must  take  it  for  granted  that  gunpowder  would 
burn,  and  fancy  the  kind  of  flashes  that  it  would  produce, 
without  the  experiment. 

The  major  then  scraped  some  particles  again  from  his 
key  into  the  flame,  to  let  the  boys  witness  it  once  more. 

While  he  was  doing  this,  a  young  lady,  who  was  one  of 
the  passengers,  came  by,  and  stopped  to  see  what  was  go- 
ing on.  Lawrence  seemed  to  be  acquainted  with  her.  He 
made  room  for  her  to  see,  and  explained  to  her  that  the 
major  was  showing  the  boys  that  iron  would  burn. 


136  BURNING    OF    IKON. 

She  looked  at  the  scintillations  for  a  moment  with  a  lan- 
guid interest,  and  then  said  she  never  knew  before  that 
iron  would  burn. 

"And  I  don't  believe  that  it  really  burns  now,"  she  said, 
"  It  only  sparkles.  It  can't  really  burn.  Yes,  I  remember 
once  I  was  at  a  lecture,  and  they  made  some  iron  burn  in 
a  jar,  but  I  thought  that  was  only  an  experiment."  So 
saying,  she  walked  away. 

Her  idea  of  an  "experiment"  was,  it  seems,  that  of  some- 
thing contrived  artificially  to  amuse  people  at  a  lecture, 
but  which  had  no  counterpart  in  nature.  An  experiment 
thus  had  no  meaning  to  her  as  the  revelation  of  a  general 
law.  It  was  a  crackle  or  a  flash,  or  something  else  odd 
and  singular,  special  to  the  occasion.  It  brought  to  her 
mind  no  conception  whatever  of  any  great  principle  or  law 
of  universal  or  permanent  force  in  the  external  world,  such 
as  it  does  really,  in  fact,  always  indicate  to  those  who  re- 
gard it  aright. 

In  the  experiment  to  which  Miss  Otis  referred,  and 
which  is  very  often  performed  in  the  lec- 
ture-room, a  slender  piece  of  iron  or  steel — 
a  portion  of  a  watch-spring,  for  example — 
with  something  to  kindle  it  at  the  extremi- 
ty, is  let  down  into  a  jar  previously  filled 
with  oxygen. 

The  effect  is  very  striking;,  and  it  always 

COMBUSTION   OF  ^  y 

IRON.  .interests  those  who  witness  it  very  much. 
But  they  ought  to  consider  it  as  the  manifestation  of  a 
universal  law  of  nature  in  respect  to  the  nature  of  iron 
and  its  relation  to  oxygen,  and  not  merely  as  a  sparkling 
light,  to  surprise  or  to  amuse  for  a  moment  by  its  bright- 
ness those  who  observe  it. 

Lawrence  repeated  several  times  the  experiment  of 
burning  the  iron  shavings  or  raspings  in  the  candle  while 
John  and  Flippy  looked  on. 


INVISIBLE    PARTICLES.  137 

"  It  is  very  pretty,"  said  Flippy,  "  but  I  don't  think  it 
is  very  splendid,  as  you  said." 

"  Splendid,  I  meant,  in  proportion  to  the  size  of  the  arti- 
cles burned,"  replied  the  major.  "  They  are  as  small  as 
the  finest  dust.  I  suppose  they  are  so  small  as  to  be  en- 
tirely invisible." 

So  saying,  the  major  took  out  a  letter  from  his  pocket 
and  scraped  his  key  over  a  portion  of  the  white  paper,  just 
as  he  had  done  over  the  candle.  The  boys,  on  examining 
the  paper,  could  see  nothing  at  all. 

"Now  if  particles  of  iron  so  minute  as  to  be  invisible 
make  such  a  sparkling  as  we  see,"  said  the  major,  "think 
what  an  inconceivably  splendid  conflagration  would  be 
produced  by  the  burning  of  a  beam  of  iron  two  feet 
through,  like  some  of  the  beams  in  our  engines !" 

"  But  it  would  be  impossible  to  burn  such  a  big  beam 
as  that,"  said  Flippy. 

"The  only  impossibility  would  be,"  replied  the  major, 
"that  of  obtaining  a  high  enough  heat  and  an  ample 
enough  supply  of  oxygen  in  proportion  to  the  size  of  the 
bars  of  iron.  I  am  not  certain,  indeed,  that  it  might  not 
be  done,  if  there  were  any  sufficient  inducement  for  at- 
tempting it." 

In  concluding  this  chapter,  I  will  say  that  any  person 
who  chooses  can  easily  repeat  the  major's  experiment  of 
showing  the  combustibility  of  iron  by  scraping  fine  parti- 
cles from  a  key,  or  the  back  of  a  kitchen-knife,  or  from  an 
old  pair  of  scissors,  or  any  other  piece  of  iron  or  steel,  into 
a  gas  or  lamp  flame.  Indeed,  these  particles  are  so  fine 
that,  if  the  scraping  is  done  beneath  any  naked  flame  that 
is  sufficiently  powerful — as,  for  example,  that  from  an  open 
gas-burner — they  will  be  drawn  up  into  it  by  the  ascend- 
ing current  of  air,  and  the  effect  will  be  all  the  more 
striking. 


138  FLAME. 


CHAPTER  XIV. 

FLAME. 

IT  was  stated  in  the  last  chapter  that  there  was  a  great 
difference  in  the  degrees  of  heat  which  different  substances 
require  for  the  commencement  of  that  process  of  rapid  com- 
bination with  oxygen,  attended  with  the  development  of 
great  heat  and  light,  which  we  call  burning,  or  combustion. 
This  principle,  in  relation  to  carbon  and  hydrogen,  the  chief 
components  of  wood  and  coal,  explains  some  very  curious 
effects  which  are  to  be  observed  in  a  common  fire  made  of 
those  substances. 

A  burning  coal  is  an  incandescent  solid ;  a  flame  is  an 
incandescent  gas.  Now  hydrogen,  in  its  ordinary  state,  is 
a  gas,  and  of  course,  when  it  is  burning,  it  forms  flame. 
Carbon,  on  the  other  hand,  in  its  ordinary  condition,  is  a 
solid,  and  thus,  when  it  is  incandescent — that  is,  when  it 
is  at  such  a  high  temperature  as  to  emit  a  bright  light — it 
forms  a  burning  coal  only ;  that  is,  an  incandescent  solid, 
and  not  a  flame. 

While  a  candle  is  burning,  the  substance  of  the  flame  is 
of  hydrogen,  though  it  is  filled  with  incandescent  particles 
of  carbon  in  an  extremely  comminuted  state.  When  we 
blow  out  the  candle,  the  combustion  of  the  hydrogen 
ceases ;  but  if  the  wick  is  still  alive,  the  fire  in  it  consists 
of  the  combustion  of  the  carbon  in  the  wick,  which  com- 
bustion still  goes  on  for  a  time  after  that  of  the  hydrogen 
is  arrested. 

The  philosophy  of  blowing  out  the  candle  is  simply  that 
the  breath  cools  the  incandescent  hydrogen  below  the  point 


MAKING   GAS   IN   A   PIPE.  139 

at  which  the  combustion  can  go  on,  and  blows  it  away.  It 
does  not  extinguish  the  wick  as  readily  as  it  does  the  flame 
partly  because  the  incandescent  carbon  is  solid  and  can  not 
be  blown  away,  and  partly  because  the  combustion  of  car- 
bon can  go  on  at  a  lower  temperature  than  that  of  hydro- 
gen. 

The  difference  between  these  two  substances  in  respect 
to  the  temperature  at  which  combustion  takes  place,  and 
to  the  appearance  which  they  respectively  present  when 
in  a  state  of  incandescence,  is  shown  still  more  strikingly 
in  the  case  of  a  fire  in  a  fireplace  or  grate,  or  in  the  open 
air.  In  all  these  cases  the  hydrogen  and  carbon  burn  sep- 
arately, and  give  rise  to  very  different  phenomena. 

In  the  first  place,  the  hydrogen,  if  it  is  desired,  can  be 
entirely  separated  from  the  carbon,  and  burned  by  itself. 
This  may  be  done  by  means  of  an  experiment  which  may 
easily  be  performed.  Take  a  common  tobacco-pipe  with  a 
long  stem ;  fill  the  bowl  nearly  full  of  any  dry  fuel,  such  as 
sawdust,  or  shavings  of  wood,  birch  bark,  or  bituminous 
coal ;  close  the  top  of  the  bowl  with  wet  clay ;  when  the 
clay  is  dry,  put  the  bowl  of  the  pipe  in  among  the  coals 
of  a  hot  fire,  placing  it  so  that  the  stem  shall  project  up- 
ward and  outward ;  the  stem  can  be  easily  supported  in 
that  position  by  allowing  it  to  rest  upon  the  andirons.  In 
a  few  minutes  smoke  will  appear  issuing  from  the  end  of 
the  pipe-stem.  This  smoke  will  consist  chiefly  of  hydro- 
gen, though  there  will  be  mingled  with  it  a  portion  of 
carbon  in  a  state  of  very  minute  division,  which  has  be- 
come separated  from  the  fuel  and  borne  away  by  the  cur- 
rent of  hydrogen.  This  gaseous  stream  issuing  from  the 
pipe  can  be  set  on  fire  by  touching  a  match  to  it,  and  it 
will  continue  to  burn  until  all  the  hydrogen  which  was 
contained  in  the  fuel  has  been  expelled. 

After  the  hydrogen  has  thus  been  exhausted,  if  you  break 


140 


FLAME. 


out  the  clay  stopper  and  examine  the  residue  left  in  the  in- 
terior of  the  pipe,  you  will  find  the  principal  portion  of  the 
carbon  remaining  in  it,  black  but  unburned.  It  was  heated 
hot  enough  to  burn,  but  it  could  not  burn,  for  burning  is 
combining  with  oxygen,  and  there  was  no  supply  of  oxy- 
gen for  it  in  the  bowl.  The  hydrogen  itself  could  only 
burn  when  it  issued  from  the  end  of  the  pipe,  where  it 
came  in  contact  with  the  air. 

This  is  the  way,  substantially,  that  gas  is  produced  for 
the  lighting  of  cities  and  towns.  Some  hydrocarbon — 
often  a  kind  of  bituminous  coal — is  placed  in  large  clay  or 
iron  vessels,  called  retorts,  which  are  set  in  brick  furnaces, 
where  hot  fires  are  built  under  them.  The  hydrogen  is 
thus  separated  from  the  carbon,  carrying  with  it,  however, 


FILLING   A    RETORT. 


ILLUMINATING   GAS. 


141 


a  considerable  quantity  of  the  latter  in  a  state  of  very 
minute  division,  and  is  stored  in  immense  gasometers, 
whence  it  is  conveyed  in  pipes  underground  wherever  it 
is  required. 

When  the  idea  was  first  proposed  of  lighting  towns  by 
gas  of  this  kind  collected  and  stored  in  immense  reservoirs 
for  the  purpose,  many  people  thought  that  such  large  ac- 
cumulations of  so  combustible  a  substance  would  be  ex- 
cessively dangerous — as  dangerous,  so  they  thought,  as  so 
much  gunpowder.  It  was  not  understood  then  as  well  as 
it  is  now  that  combustion  can  only  take  place  in  such 
cases  by  the  action  of  oxygen,  and  that,  if  an  opening  were 
made  into  a  gasometer,  and  fire  applied,  the  gas  could  only 


UA8-HOLDKB. 


142  FLAME. 

burn  as  fast  as  it  came  out  to  where  the  oxygen  could  come 
in  contact  with  it.  It  is  said  that  one  of  the  inventors  of 
this  method  of  lighting,  on  a  certain  occasion,  in  order  to 
prove  the  safety  of  it,  tried  the  experiment  of  lighting  a 
stream  of  the  gas  coming  from  an  orifice,  much  to  the 
alarm  of  the  spectators. 

The  case  of  gas  is  different  from  that  of  gunpowder, 
which  has  its  store  of  oxygen  in  its  own  composition,  and 
so  does  not  depend  at  all  upon  that  in  the  surrounding  air. 

The  mass  of  carbon  that  remains  in  the  gas  retorts  after 
the  hydrogen  has  been  all  evolved  from  it  is  afterward 
taken  out,  and  forms  what  is  called  coke.  This  may  be 
burned  afterward  for  the  purpose  of  producing  heat,  though 
it  will  give  out  very  little  flame  in  being  thus  burned,  inas- 
much as  all  the  hydrogen,  which  alone  can  produce  a  dis- 
tinct flame,  has  been  expelled  from  it  by  the  heat  of  the 
furnaces. 

This  heat,  however,  though  it  was  sufficient  to  keep  the 
carbon  within  the  retorts  red-hot  for  a  long  time,  could 
not  cause  it  to  burn,  because  there  was  no  oxygen  within 
the  retorts  to  combine  with  it,  and  thus  produce  combus- 
tion. 

Now,  though  in  the  case  of  an  open  fire  the  combustion 
of  the  hydrogen  and  of  the  carbon  are  not  separated  thus 
completely,  but  mingle  or  alternate  with  each  other  in  a 
confused  and  irregular  manner,  the  difference  between 
them  is  very  obvious  to  those  who  attentively  watch  the 
phenomena,  and  to  understand  the  action  of  these  two  sub- 
stances greatly  adds  to  the  interest  and  pleasure  of  making 
a  fire  in  the  woods,  or  in  any  other  place. 

For  example,  a  boy  named  Eugene,  and  his  sister  Viola, 
went  out  one  day  to  an  open  field  in  the  border  of  a  wood, 
behind  their  house,  to  build  a  fire.  Eugene  carried  some 
coals  in  a  pan.  These  coals  were,  of  course,  incandescent 


BUILDING    A    FIEE.  143 

carbon.  They  were  slowly  burning  from  the  outside  in- 
ward as  the  oxygen  of  the  air  came  in  contact  with  the 
successive  portions  of  them.  The  oxygen,  of  course,  only 
combined  with  the  particles  of  carbon,  leaving  the  earthy 
matter  which  the  wood  from  which  the  coals  had  been  pro- 
duced contained,  in  the  form  of  a  thin  white  film  around 
the  coals.  From  time  to  time  Eugene  stopped  to  blow  this 
film  of  ashes  away,  and  this  made  the  coals  brighten  up  by 
admitting  the  air  more  freely  to  the  particles  of  carbon 
below. 

Eugene  and  Viola  stopped  once  or  twice  to  watch  these 
little  films  form  on  the  surface  of  the  coals.  But  they  did 
not  know  any  thing  about  the  nature  of  them,  nor  what 
the  reason  was  that  it  made  the  coals  brighten  up  to  blow 
them  away. 

Presently  they  came  to  the  place  where  they  were  going 
to  build  their  fire.  Eugene  laid  his  fire-pan,  with  the  coals 
in  it,  down  upon  the  grass,  and  began  to  gather  wood  for 
his  fire.  Viola  helped  him  to  find  and  bring  the  wood. 
They  laid  down  two  of  their  sticks  upon  the  ground  for 
andirons. 

"  Our  fire  will  burn  better  if  we  have  andirons,"  said 
Eugene. 

This  was  true ;  for,  by  raising  the  wood  which  was  in- 
tended to  be  burned  above  the  ground,  the  air  could  bring 
its  oxygen  to  it  more  easily. 

Then  Eugene  laid  some  sticks  across  his  andirons,  plac- 
ing two  of  them  pretty  near  together,  but  leaving  a  little 
opening  between. 

"  Now,"  said  he, "  we  must  put  on  the  coals." 

So  he  poured  the  coals  over  the  interstice,  or  opening, 
between  the  two  sticks  of  wood.  The  coals  had,  however, 
been  lying  in  the  pan  so  long,  where  but  little  oxygen 
could  gain  access  to  them,  that  the  combustion  had  gone 


144  FLAME. 

on  very  slowly.  But  when  they  were  placed  in  this  new 
position,  the  air  around  them  was  heated  and  swelled,  and 
so  became  lighter  and  rose,  while  a  fresh  supply,  bringing 
more  oxygen,  came  up  through  the  interstice ;  and  this  ox- 
ygen, combining  at  once  with  the  carbon  of  the  coals,  be- 
gan to  give  out  more  heat  and  light  by  the  intensity  of  the 
action — that  is  to  say,  in  other  words,  the  coals  began  to 
brighten  up  immediately. 

But  the  wood  which  lay  next  the  coals  could  not  take 
fire  until  it  was  heated  up,  by  the  contact  of  the  coals,  to 
the  point  of  combustion.  This,  of  course,  required  some 
little  time.  Very  soon,  however,  the  outer  layers  became 
hot  enough  for  the  combustion  of  the  carbon,  but  not 
enough  for  that  of  the  hydrogen.  The  hydrogen  was,  how- 
ever, set  free  and  began  to  rise,  carrying  up  with  it  a  great 
quantity  of  fine  particles  of  carbon,  forming  a  little  cloud, 
which  went  curling  upward  into  the  air. 

"  See,  Viola,"  said  Eugene,  "  it  is  beginning  to  smoke. 
We  want  some  kindling  stuff  to  make  it  blaze.  Go  and 
see  if  you  can  find  some  kindling  stuff." 

So  Viola  began  to  look  around  for  small  slender  sticks, 
and  dried  leaves,  and  other  such  light  fuel.  She  and  Eu- 
gene knew,  both  from  their  having  been  so  told,  and  also 
from  their  own  experience  on  former  occasions,  that  a  little 
heap  of  such  things  would  take  fire  more  easily  and  burn 
faster  than  solid  logs  of  wood,  but  they  did  not  know  at 
all  that  the  reason  why  they  would  do  so  was  because  the 
openings  and  interstices  between  them  allowed  each  por- 
tion of  the  whole  mass  to  be  surrounded  by  air,  so  that 
every  part  had  a  supply  of  oxygen  close  at  hand,  while  in 
a  solid  piece  of  wood  the  whole  interior  of  the  mass  is 
wholly  cut  off  from  the  access  of  oxygen,  and  can  only  be 
reached  by  it  gradually,  as  the  outer  parts  are  burned 
away. 


SMOKE    AND    BLAZE.  145 

Viola  soon  brought  a  supply  of  kindling  stuff,  and  Eu- 
gene put  it  on  the  fire.  The  fire  worked  up  slowly  through 
it,  burning  the  carbon — for  the  heat  was  great  enough  for 
the  combustion  of  carbon — but  only  setting  the  hydrogen 
free  without  burning  it,  for  the  heat  was  not  sufficient  yet, 
in  any  part,  to  allow  the  rapid  combination  of  hydrogen 
and  oxygen  to  commence ;  in  other  words,  for  the  hydro- 
gen to  take  fire.  The  hydrogen  was  set  free,  however,  in 
great  quantities,  and  came  up  through  the  kindling,  min- 
gled with  the  other  gases,  and  with  great  quantities  of 
finely  divided  carbon.  In  other  words,  the  fire  sent  up 
dense  volumes  of  smoke,  but  did  not  blaze. 

"  Viola,"  said  Eugene, "  if  we  only  had  a  match,  or  piece 
of  lighted  paper  to  touch  to  our  fire,  we  could  set  it  a-blaz- 
ing  in  an  instant." 

Eugene  spoke  very  correctly  in  saying  this.  He  would 
have  been  equally  correct  and  more  scientific  if  he  had 
said, 

"The  carbon  is  burning  finely, Viola,  and  the  hydrogen 
is  coming  up  very  fast ;  but  it  has  not  got  hot  enough  yet 
any  where  for  the  hydrogen  to  take  fire.  If  we  only  had 
a  match  or  a  lamp-lighter  with  the  hydrogen  burning,  and 
could  touch  it  to  our  fire,  it  would  light  up  the  hydrogen 
in  that  in  an  instant." 

It  may  seem  strange  that  the  heat  from  the  small  flame 
of  a  match  or  a  lamp-lighter  should  be  so  much  more  ef- 
fective than  all  the  heat  of  the  red-hot  and  burning  carbon 
in  a  fire  which  smokes  but  does  not  blaze.  But  the  truth 
is,  that  though  the  heat  of  the  coals  may  be  much  greater 
in  amount,  it  is  not  so  intense,  in  any  one  point,  as  the  heat 
of  the  smallest  flame.  It  is  in  no  part  hot  enough  to  bring 
the  hydrogen  up  to  the  point  of  combustion  for  hydrogen, 
while  the  little  flame  is  hot  enough,  though  the  heat  is  cir- 
cumscribed within  a  very  small  space. 

G 


146  FLAME. 

Nor  is  it  at  all  necessary  that  it  should  be  extended  ;  for 
if  the  right  intensity  of  heat  is  attained  at  any  one  point, 
the  hydrogen  will  at  once  begin  to  combine  with  the  oxy- 
gen at  that  point,  and,  in  so  doing,  will  develop  heat  much 
faster  than  while  the  carbon  only  was  burning,  and  will 
spread  the  combustion  almost  instantly  through  the  fire, 
wherever  there  are  streams  of  hydrogen  issuing  from  the 
fuel. 

"I'm  sorry  we  have  not  any  matches,"  said  Viola.  "But 
can't  you  make  it  burn  by  blowing  it  ?" 

"  I'll  try,"  said  Eugene ;  and,  so  saying,  he  kneeled  down 
before  the  fire  and  began  to  blow  with  his  breath  under 
the  fore-stick.  In  this  way  he  sent  a  current  of  air  among 
the  coals  which  supplied  them  with  oxygen  faster  than  be- 
fore. The  oxygen  then  combined  faster  with  the  carbon, 
and  this  developed  more  heat,  until  in  a  few  minutes  the 
heat  was  raised  in  some  one  point  high  enough  to  reach  the 
point  of  combustion  of  hydrogen,  when  all  the  hydrogen 
at  once  took  fire,  or,  in  other  words,  the  fire  burst  into  a 
blaze. 


THE    GULF    STREAM.  147 


CHAPTER  XV. 

THE    BANKS    OF   NEWFOUNDLAND. 

A  STEAM-SHIP  sailing  from  New  York  to  Liverpool  comes, 
in  the  course  of  three  or  four  days  after  leaving  port,  into 
a  part  of  the  sea,  off  the  coast  of  Newfoundland,  where  the 
immense  current  of  warm  water  from  the  Gulf  of  Mexico 
encounters  the  vast  stream  of  floating  ice  and  icebergs 
which  pours  down  from  Baffin's  Bay  to  meet  it.  The 
causes  which  produce  the  vast  and  ceaseless  flow  of  these 
two  currents  are  very  curious,  but  I  can  not  stop  to  explain 
them  here.  The  magnitude  of  them  is  enormous,  surpass- 
ing entirely,  as  they  do,  the  power  of  the  human  imagina- 
tion to  grasp  them.  The  Gulf  Stream  is  often  compared 
to  a  river  flowing  through  the  ocean.  It  is  a  river  some 
thousands  of  miles  long,  fifty  miles  wide,  and  a  thousand 
feet  deep,  and  flows  incessantly  at  the  rate  of  four  or  five 
miles  an  hour,  making  a  stream  about  as  large  as  several 
thousand  Mississippi  rivers  all  in  one !  It  is  an  example 
of  the  conveyance  of  heat  by  the  transportation  of  the 
heated  substance  and  conduction,  or  convection,  the  grand- 
est, probably,  both  in  respect  to  the  magnitude  of  the  ac- 
tion itself  and  of  the  effects  produced  by  it,  that  is  known 
to  man. 

The  encounter  between  this  stream  of  warm  water  from 
the  south  and  the  current  of  cold  water,  bringing  at  cer- 
tain seasons  of  the  year  vast  mountains  and  fields  of  ice, 
produces  some  very  curious  effects.  The  rocks,  and  gravel, 
and  sand  brought  by  the  ice  are  dropped,  when  the  ice 
melts,  in  the  region  where  the  warm  water  meets  the  arctic 
stream. 


148  THE    BANKS    OF    NEWFOUNDLAND. 


ICEBEBGS  DEPOSITING   BOOKS   AND  GRAVEL. 

These  deposits,  which  have  been  going  on  for  many 
thousands  of  years — and  no  one  knows  how  much  longer — 
taken  in  connection  with  other  causes,  have  produced  vast 
shoals,  called  the  Banks,  which  are  the  resort  of  immense 
quantities  of  fish,  .of  the  kinds  that  find  their  food  best  in 
shallow  water.  The  gathering  of  the  fish  here  brings  fleets 
of  fishermen.  The  encounter,  too,  of  the  warm  and  moist 
air  which  arises  from  the  water  of  the  Gulf  Stream,  with  the 
chill  produced  by  the  icebergs  and  ice-fields,  and  the  cold 
current  of  water,  fills  the  air  with  fogs  and  mists,  and  pro- 
duces gusts  of  wind  and  scudding  clouds,  which  chase  each 
other  incessantly  over  the  surface  of  the  water. 

Thus  the  confluence  of  the  torrid  and  frigid  currents  at 
this  point  leads  directly  and  indirectly  to  a  heterogeneous 
assemblage  of  fogs,  mists,  squalls,  shoals,  icebergs,  fish,  and 
fishermen,  such  that  it  requires  great  tact  and  skill  on  the 
part  of  the  organized  intelligence  of  a  sea-going  steamer 
to  carry  the  ship  safely  through  it. 

The  difficulty  is  greater  from  the  fact  that  there  is  found 
to  be  no  serious  advantage  gained  by  any  slacking  of  the 
speed.  So  the  vast  construction,  with  its  town  of  a  thou- 


DANGERS  ON  THE  BANKS.  149 

sand  inhabitants,  more  or  less,  on  board,  drives  steadily  on, 
at  a  speed  three  times  as  fast  as  a  horse  trots  on  a  journey, 
through  fogs,  mists,  and  squalls,  and  among  fishing-boats, 
ships,  and  returning  steamers,  trusting  to  the  vigilance  and 
alertness  of  that  many-eyed  and  many-handed  organization 
formed  by  the  ship's  company.  They  feel  for  the  vicinity 
of  ice  by  a  thermometer  let  down  into  the  water.  They 
find  their  way  by  catching  with  the  sextant  occasional 
glimpses  t>f  the  sun,  his  form  half  revealed  at  intervals 
through  the  driving  mists  and  rain.  They  warn  the  invis- 
ible fishing-boats  of  their  approach  by  blowing  the  steam- 
whistle,  expecting  them  to  answer  with  muskets  or  horns. 
One  would  not  suppose  that  such  precautions  as  these 
would  be  at  all  suificient  to  make  the  passage  through  such 
a  way  -even  tolerably  safe.  But  the  sea  is  wide,  and  the 
obstructions,  though  numerous  in  the  aggregate,  are,  in 
fact,  in  view  of  the  vastness  of  the  expanse,  relatively  rare, 
and  the  ships  of  the  Cunard  line  have  been  traversing  it 
incessantly  for  a  quarter  of  a  century  without  any  serious 
harm. 

It  is  not  at  all  surprising,  however,  that  some  of  the  pas- 
sengers, and  especially  ladies,  feel  a  little  nervous  some- 
times while  traversing  this  part  of  the  sea,  especially  if 
they  rightly  understand  the  state  of  things  around  them. 

One  day,  while  the  steamer  was  on  the  Banks,  at  about  a 
quarter  past  eleven  o'clock  by  the  steamer's  time,  which 
was  really  the  time  of  her  position  at  noon  the  day  before, 
so  that  it  was  actually,  where  she  then  was,  nearly  twelve, 
the  boys  were  on  deck.  The  water  was  smooth,  and  the 
air  was  really  calm,  though  quite  a  breeze  was  produced 
along  the  decks  by  the  swift  motion  of  the  vessel.  It  was 
not  raining,  but  a  thin  fog  covered  the  water  in  every  part, 
and  veiled  the  sky,  though  the  form  of  the  sun  could  be 
seen  sometimes  faintly  showing  itself  through  it.  Two  or 


150  THE    BANKS    OF    NEWFOUNDLAND. 

three  of  the  officers  were  on  the  deck,  with  their  sextants 
in  their  hands,  trying  to  obtain  an  observation. 

Another  officer  had  just  been  superintending  the  opera- 
tion of  heaving  the  log,  and  twenty  or  thirty  men  were  at 
work  drawing  in  the  log-line,  which,  though  it  is  only  a 
stout  cord  to  be  drawn  through  the  water,  comes  in  very 
hard.  John  and  Flippy  had  been  watching  this  operation, 
and  when  it  was  completed  they  went  to  a  place  where 
Lawrence  was  seated,  near  one  of  the  smoke-pipes.  As 
these  smoke-pipes  are  ten  or  twelve  feet  in  diameter,  they 
afford  a  very  good  shelter  from  the  wind ;  and  as  they  be- 
come very  hot  by  the  vast  quantity  of  intensely -heated 
gases  that  are  coming  up  through  them,  they  form  excel- 
lent stoves  of  prodigious  magnitude,  around  which  the 
passengers  find  it  very  comfortable  to  gather  on  cold  and 
chilly  days.  Lawrence  was  seated  in  a  folding  chair.  The 
boys  took  seats  upon  camp-stools  by  the  side  of  him. 

"  Now,  Flippy,"  said  Lawrence,  "  it  is  your  turn  to  see 
whether  you  can  repeat  the  substance  of  what  I  told  you 
about  the  smoke  coming  out  of  the  chimney." 

Flippy  looked  up,  and  saw  an  immense  volume  of  smoke 
emerging  from  the  chimney  and  passing  off  toward  the 
stern  until  it  was  lost  in  the  fog. 

"Well,"  said  Flippy,  "I'll  try.  All  that  smoke— that 
is,  all  the  black  part  of  it — is  made  up  of  fine  particles  of 
carbon  from  the  coal  that  could  not  find  any  oxygen  to 
burn  it  in  the  fire." 

"Good !"  said  Lawrence ;  "that  is  just  it.  Quite  a  large 
portion  of  every  ton  of  coal  that  they  put  into  the  furnaces 
comes  out  in  this  way  without  being  burnt.  Heat  alone 
won't  make  it  burn  without  oxygen.  If  it  comes  up 
through  the  hottest  part  of  the  fire  at  a  place  where  there 
is  not  oxygen  for  it,  it  will  not  be  burned,  but  will  come 
up  through  the  chimney  in  smoke.  So  they  not  only  lose 


THE    BLACK    COUNTRY.  151 

a  great  deal  of  coal  by  having  it  pass  through  the  furnaces 
without  giving  out  any  heat,  but  the  smoke  which  it  makes 
on  land  sometimes  does  a  great  deal  of  mischief.  I  can't 
tell  you  how  much  time  and  money  has  been  spent  in  En- 
gland and  in  other  manufacturing  countries  in  trying  to 
contrive  means  to  prevent  this  carbon  from  getting  through 
the  fire  without  being  burned." 

"  There  is  a  great  region  in  England,"  continued  Law- 
rence, "  where  there  are  so  many  coal  mines,  and  iron 
mines,  and  founderies,  and  machine-shops,  all  requiring  im- 
mense furnaces  and  chimneys,  that  the  whole  country  is 
filled  with  the  smoke.  They  call  it  the  Black  Country." 

"  I  should  like  to  see  it,"  said  Flippy. 

"  It  is  very  likely  that  you  will  go  through  it,"  said  Law- 
rence. "  It  is  very  interesting  to  visit  the  works  and  wit- 
ness the  immense  operations  that  are  performed  in  them, 
but  the  smoke  is  a  terrible  nuisance.  It  injures  the  air  for 
breathing,  kills  vegetation,  and  blackens  every  thing.  And 
it  is  all  the  more  vexatious  because  it  is  only  the  waste  of 
a  good  thing  that  occasions  it.  If  the  carbon  would  only 
stay  in  the  fire  and  be  burned,  it  would  do  good  by  giving 
out  more  heat." 

"  I  don't  believe  but  that  I  could  find  out  some  way," 
said  Flippy. 

"Perhaps  you  may  do  it  when  you  are  a  man,"  said 
Lawrence,  "  if  you  make  as  much  progress  until  that  time 
in  looking  into  these  things  as  you  have  done  so  far  during 
this  voyage.  A  great  many  men  have  tried,  and  some 
smoke-consuming  furnaces,  as  they  are  called,  have  been 
invented,  and,  to  a  certain  extent,  they  are  successful ;  but 
they  do  not  effectually  remedy  the  evil,  except  in  the  case 
of  lamps.  A  common  lamp  will  smoke  if  it  is  turned  up 
too  high — that  is,  if  the  wick  furnishes  carbon  from  the  oil 
faster  than  the  air  around  can  furnish  oxygen  to  combine 


152 


THE    BANKS    OF    NEWFOUNDLAND. 


with  it.     Did  you  ever  hear  of  an  Argand  lamp  or  an  Ar- 
gand burner  ?" 

John  said  he  had,  but  Flippy  did  not  remember  whether 
he  had  or  not. 

Lawrence  then  went  on  to  explain  the  very  simple  con- 
trivance which  was  invented  by  a  man  named  Argand  for 
supplying  a  double  current  of  oxygen  to  the  wick  of  a 
lamp,  arid  also  supplying  it  faster,  so  as  to  consume  com- 
pletely a  much  larger  quantity  of  carbon  than  would  other- 
wise be  possible. 

This  contrivance  consists  of  making  the  wick  cylindrical, 
and  admitting  the  air  on  the  inside  as  well  as  on  the  out- 
side of  it,  and  then,  by  placing  a  glass  chimney  over  it, 
producing  a  draft  by  the  ascending  current  of  air,  which 
has  the  effect  of  bringing  the  supply  of  air  in  faster. 

The  engraving  shows  how  this  is  done. 
The  wick  is  seen  in  the  centre,  the  middle 
arrow  below  showing  how  the  air  passes  up 
and  supplies  oxygen  to  the  inside  surface 
of  the  flame.  The  other  arrows  show  how 
it  passes  up  to  supply  the  outer  surface.  H 
is  the  glass  chimney  which  creates  the  draft, 
and  K  the  brass  tube  in  which  it  is  set  to 
hold  it  firm. 

"  This  contrivance,"  continued  Lawrence, 
after  he  had  explained  it  to  the  boys,  which 
he  did  by  rolling  up  two  pieces  of  paper  and 
placing  them  together  in  such  a  way  as  to 
represent  the  form  of  the  wick  and  the  rela- 
tive positions  of  the  wick  and  the  glass, 
"  was  found  to  work  admirably,  and  it  has 
been  applied  to  a  great  number  and  variety 
of  lamps  and  gas-burners.  And  whenever 
BUBNKE.  you  see  a  light  managed  on  this  principle — 


FOG   AT   NIGHT.  153 

that  is,  with  the  flame,  whatever  produces  it,  in  a  cylindri- 
cal form,  with  a  current  of  air  on  the  inside  as  well  as  the 
outside  of  it,  and  a  glass  chimney  to  increase  the  draft — 
you  may  pretty  safely  infer  that  it  is  an  Argand  burner." 

Just  at  this  moment  it  struck  "  eight  bells,"  which 
showed  that  the  captain  had  decided  from  his  observa- 
tions, or  in  some  other  way,  that  it  was  noon  where  they 
were,  though  only  a  little  more  than  half  past  eleven  by 
the  time  which  they  had  brought  with  them  from  the  noon 
of  the  day  before.  A  moment  afterward  a  bell  rang  for 
luncheon,  and  Lawrence  and  the  boys  rose  to  go  below. 
They  would  have  been  obliged  to  go  below  at  any  rate 
without  this  summons,  for  the  fog  and  the  clouds  had  be- 
come more  dense,  and  a  misty  rain  was  falling  upon  the 
decks.  In  the  course  of  the  afternoon  the  wind  rose,  and 
the  ship  soon  began  to  move  uneasily  through  the  water, 
indicating  that  the  sea  was  growing  rough.  There  were 
fewer  persons  at  dinner  that  day,  and  fewer  still  at  tea. 
The  motion  increased  in  the  evening,  and  Lawrence  rec- 
ommended to  John  to  climb  up  into  his  berth  at  an  early 
hour,  so  as  to  get  asleep  before  he  became  sick.  John  was 
very  ready  to  do  so. 

He  slept  soundly  for  some  hours,  but  at  length  he  was 
awaked  by  a  loud  trampling  over  head.  He  opened  his 
eyes,  but  it  was  almost  entirely  dark,  and  so  he  knew  that 
it  was  after  twelve  o'clock.  The  candle  which  burns  in  a 
little  closed  box,  with  glass  sides,  between  each  two  state- 
rooms, is  always  put  out  at  midnight,  unless  in  special  cases 
an  arrangement  is  made  for  burning  it  through  the  night. 

He  listened,  and  heard  the  shrill  whistle  of  the  boat- 
swain, and  the  song  or  chant  of  the  sailors,  indicating  that 
they  were  "  heaving  away"  at  something  or  other. 

John  put  his  head  over  the  edge  of  his  berth,  and  looked 
down  to  see  if  he  could  tell  whether  Lawrence  was  awake. 

G2 


154  THE    BANKS    OF    NEWFOUNDLAND. 

"  Lawrence,"  said  he,  "  are  you  awake  ?" 

"  Yes,"  said  Lawrence. 

"What  do  you  suppose  they  are  doing  on  deck?" 

"  Making  sail,  or  taking  in  sail,"  said  Lawrence, "  or  some- 
thing or  other  of  that  sort.  It  is  all  right,  I've  no  doubt." 

So  John  lay  down  again.  But  in  a  moment  more  he 
heard  the  shriek  of  a  steam-whistle  a  great  way  off  for- 
ward. 

"  Lawrence,"  said  John,  "  what  do  you  suppose  that 
whistle  means  ?" 

"  Perhaps  it  is  the  boiler  whistling  for  more  water,"  said 
Lawrence. 

"  Nonsense  !"  said  John.  "  The  boiler  would  not  whistle 
for  water." 

"  Yes,"  replied  Lawrence,  "  they  have  a  contrivance  in 
some  boilers  by  which,  when  the  water  gets  too  low,  there 
is  a  float  that  settles  down,  and  opens  a  valve,  and  lets 
steam  out  to  whistle  for  them  to  pump  in  more  water." 

"  No,"  said  John, "  that  isn't  the  plan  in  our  boiler.  They 
have  a  glass  tube.  The  engineer  showed  it  to  me." 

"Then  perhaps  it  is  the  fog,"  said  Lawrence.  "They 
may  be  afraid  that  there  is  an  iceberg  ahead,  in  the  fog." 

"  That  would  not  do  any  good,"  said  John.  "  An  ice- 
berg would  not  get  out  of  their  way  for  whistling." 

"  Then  perhaps  there  may  be  fishing-boats,"  said  Law- 
rence, "  and  they  want  to  warn  them  that  we  are  coming." 

"  It  may  be  that,"  said  John. 

"  At  any  rate,  it  is  nothing  to  us  what  it  is,"  said  Law- 
rence, "  so  lie  down  and  go  to  sleep." 

So  John  lay  down  and  went  to  sleep,  and  slept  soundly 
till  morning. 


GOING  DOWN   BY    LADDERS. 


-MODES    OF    ENTERING    A    COAL-MINE.  157 


CHAPTER  XVI. 

MISS    ALMIEA. 

"  FLIPPY,"  said  Lawrence  one  day  to  Flippy,  as  he  and 
the  boys  were  sitting  at  the  table  after  tea,  talking  to- 
gether on  various  subjects, "  do  you  mean  to  go  down  into 
a  coal-mine  when  you  get  to  England  ?" 

"  Yes,"  replied  Flippy,  "  indeed  I  do— that  is,  if  I  can 
get  a  chance.  Wouldn't  you  ?" 

"  I  think  I  should,"  replied  Lawrence.  "  At  any  rate,  I 
think  there  would  be  more  sense  in  it  than  in  your  getting 
the  stokers  to  let  you  down  into  the  coal-hole  on  board 
ship.  But  how  do  you  intend  to  go  down?  There  are 
two  or  three  ways.  You  can  go  down  as  the  workmen  do, 
or  as  visitors  do." 

Flippy  wished  to  know  what  the  diiferent  ways  were. 

"  You  can  go  down  as  the  workmen  do  sometimes,"  said 
Lawrence, "  in  a  kind  of  an  iron  tub." 

"  Like  the  bucket  for  the  cinders  here  ?"  asked  Flippy. 

"Yes,  only  bigger,"  said  Lawrence;  "it* is  big  enough, 
usually,  to  hold  several  men." 

"  And  what  are  the  other  ways  ?"  asked  Flippy. 

"  The  officers  and  managers  of  the  mine  generally  go  up 
and  down  in  a  kind  of  iron  cage,  which  is  cleaner  and  more 
comfortable,  and  also  safer  than  the  tub.  Then  there  is 
another  way  still,  which  the  workmen  use  sometimes  and 
in  some  places,  and  that  is  by  ladders." 

"That's  the  way  I'll  take,"  said  Flippy,  eagerly.  "I 
should  like  to  go  down  into  a  mine  by  a  ladder." 

"  It  would  be  hard  work,"  said  Lawrence.    "  The  mines 


158  MISS    ALMIBA. 

are,  some  of  them,  very  deep.  But,  whatever  way  you  take 
for  going  down,  there  is  one  thing  that  I  think  is  import- 
ant, and  that  is  that  you  should  learn  all  you  can  about 
coal  before  you  go.  The  more  you  know  about  it,  the  more 
interested  you  will  be  in  seeing  it.  And,  if  you  like,  I  will 
tell  you  something  more  about  it  now." 

The  boys  said  that  they  should  like  to  hear. 

"  Well,  then,  said  Lawrence,"  when  you  go  down  into  a 
mine,  and  see  the  men  heaving  out  the  coal,  and  blocks  of 
it  lying  about,  you  must  think  that  each  lump  that  you  see 
contains  a  certain  amount  of  heat  in  reserve,  or,  rather,  the 
power  of  giving  out  a  certain  amount  of  heat  when  the 
carbon  and  hydrogen  contained  in  it  is  combined  again 
with  oxygen.  It  has  the  power  to  produce  a  certain 
amount  and  no  more.  You  can  not  possibly  burn  it  in  any 
way  to  prevent  its  giving  out  so  much,  and  you  can  not 
possibly  burn  it  in  such  a  way  as  to  make  it  give  out 
more." 

"  Yes,"  said  Flippy, "  you  can  blow  it  with  the  bellows. 
When  a  blacksmith  blows  his  fire  with  the  bellows  he  makes 
it  a  great  deal  hotter" 

"  True,"  said  Lawrence,  "  he  makes  the  fire  hotter,  but 
does  not  he  make  the  coals  burn  out  faster  ?" 

"  Yes,"  said  Flippy, "  of  course  the  coals  burn  out  faster." 

"  So  you  see  there  is  no  gain  in  the  amount,"  replied 
Lawrence,  "but  only  an  increase  of  intensity  by  shortening 
the  time.  You  can  have  your  heat  all  at  once  by  carrying 
on  the  combustion  very  rapidly,  or  you  can  make  the  com- 
bustion go  on  more  slowly  by  not  sending  in  a  rapid  sup- 
ply of  oxygen,  and  so  have  a  lower  degree  of  heat  contin- 
ued for  a  longer  time.  It  has  been  proved  by  the  most 
careful  experiments  that  the  whole  amount  developed  by 
the  same  quantity  of  fuel,  whether  it  is.  burned  fast  or 
slowly,  is  exactly  the  same." 


WHY   THE    WOODS    ARE    COOL    IN    SUMMER.  161 

"  And  there  is  another  thing  that  is  very  curious,"  con- 
tinued Lawrence,  "  and  that  is,  that  this  amount  of  heat 
which  coal  or  any  fuel  gives  out  in  burning  is  exactly  the 
same  as  that  which  was  expended  by  the  sun  in  the  leaves 
of  the  plants  in  producing  the  vegetable  substance  out  of 
which  the  coal  was  formed ;  that  is  to  say,  the  carbon 
and  oxygen,  and  the  hydrogen  and  oxygen,  in  coming  to- 
gether again  in  burning,  give  out  precisely  the  same  amount 
of  heat  with  that  which  they  absorbed  from  the  sun  in  be- 
ing separated. 

So,  when  you  take  a  walk  in  the  woods  in  a  hot  summer's 
day,  and  find  how  cool  it  is,  it  is  curious  to  think  that  the 
heat  of  the  sun  that  has  disappeared  among  the  trees  is  not 
lost,  but  is  laid  up,  as  it  were,  in  the  wood,  the  sun  having 
expended  it  in  separating  the  carbon  from  the  oxygen,  and 
that  it  will  all  come  out  again  when  the  oxygen  is  restored. 
Thus  a  farmer,  if  he  only  understood  what  was  going  on 
about  him  when  walking  through  his  wood-lot  in  June  and 
July,  and  finding  it  so  cool  under  the  trees,  would  not  only 
enjoy  the  coolness  at  the  time,  but  would  take  pleasure  in 
thinking  that  the  sun  was  laying  up  all  that  surplus  heat 
in  the  wood,  to  come  out  again  in  due  time  to  cheer  his 
fireside  with  the  glow  of  its  brightness  and  warmth  in  the 
long  evenings  of  December  and  January." 

Now  it  happened  that  while  Lawrence  was  talking  in 
this  way  to  the  boys,  there  was  a  young  lady  sitting  at 
the  table  a  little  way  beyond  him,  reading.  Lawrence 
had  become  informally  introduced  to  her  some  time  before 
through  the  major;  or,  rather,  he  had  not  been  introduced 
to  her  at  all,  but  had  formed  part  of  a  group  with  her,  who 
were  engaged  in  conversation,  and  which  both  she  herself 
and  Lawrence  joined.  They  had  continued  this  acquaint- 
ance by  meeting  on  several  subsequent  occasions. 

It  is  necessary  to  be  very  careful,  in  making  acquaint- 


102  MISS    ALMIRA. 

ances  on  board  such  a  steamer  as  those  traversing  the  At- 
lantic, to  have  decisive  evidence  of  some  kind  in  regard  to 
the  respectability  and  character  of  the  persons  you  are  to 
associate  with.  But  it  is  not  at  all  necessary  that  this  ev- 
idence should  come  in  the  form  of  a  regular  introduction, 
nor,  indeed,  would  this  be  generally  possible.  The  com- 
pany of  passengers  come  together,  in  general,  as  total 
strangers  to  each  other,  and  with  no  mutual  acquaint- 
ances, so  that  formal  introductions  are,  in  general,  out  of 
the  question.  If  the  passengers  were  to  enjoy  no  social 
intercourse  except  so  far  as  they  could  be  regularly  intro- 
duced to  each  other,  they  would  form  a  very  morose,  ex- 
clusive, and  unsocial  company  all  the  voyage. 

When  Lawrence  found  that  the  young  lady  was  inclined 
to  pay  attention  to  what  he  was  saying  to  the  boys,  he 
turned  toward  her,  and  said  that  he  had  been  whiling  away 
some  of  the  time  of  the  voyage  in  giving  the  boys  some 
instruction  on  the  subject  of  combustion  and  heat. 

"  Yes,"  she  replied,  "  I  have  been  very  much  interested 
in  what  you  said  about  the  heat  from  the  sun  being  stored 
up  in  trees  and  plants.  I  always  supposed  that  it  was  the 
shade  that  made  it  cool  in  the  woods." 

"  It  is  the  shalie  in  part,  I  have  no  doubt,"  said  Law- 
rence, "and  it  is  also  in  part  owing  to  the  evaporation 
of  the  moisture  on  the  surface  of  the  leaves  and  on  the 
ground ;  but  it  is  owing  still  more  to  the  absorption  of  the 
heat  of  the  sun  by  the  leaves  in  the  formation  of  vegetable 
substances.  The  heat  remains  concealed  in  some  myste- 
rious way  in  the  substance  of  the  plant,  and  entirely  sus- 
pended in  its  action,  as  heat,  until  it  is  afterward  liberated 
by  combustion." 

Lawrence  then  went  on  to  explain  briefly  to  Miss  Al- 
mira — for  that  was  the  name  by  which  he  addressed  her — 
what  he  had  taught  the  boys  about  the  process  of  vegeta- 


WHERE    THE    COAL    CAME    FROM.  165 

tion  being  substantially  a  process  of  separating  carbon  and 
hydrogen  from  oxygen  by  the  power  of  heat  and  the  other 
radiants  from  the  sun,  and  that  combustion  was  nothing 
more  than  the  violent  return  of  the  oxygen  to  its  former 
combination  with  them,  thus  releasing  and  setting  free  the 
forces  which  had  been  derived  from  the  sun  and  were  stored 
up  in  the  wood  or  the  other  vegetable  substances. 

"  So  you  see,"  said  Lawrence,  "  that  the  sun  in  the  sum- 
mer pours  his  beams  over  all  the  forests  and  fields  of  our 
hemisphere,  and  deposits  a  vast  portion  of  his  heat  and 
force  in  the  plants  and  trees  which  he  has  made  to  grow 
there.  When,  in  the  fall,  he  goes  south  of  the  equator,  he 
leaves  all  this  heat  and  force  behind  him,  to  help  us  against 
the  cold  which  comes  from  the  north  to  occupy  his  place 
while  he  is  gone.  In  the  same  manner,  in  one  age  of  the 
world  he  makes  vast  deposits  of  his  power  in  forms  of  veg- 
etation very  different  from  those  of  the  present  day,  grow- 
ing in  swamps,  and  morasses,  and  in  grounds  half  sub- 
merged, so  that,  when  they  fall,  they  fall  into  the  water, 
and  are  in  a  great  measure  protected  from  decay.  There 
they  in  time  form  vegetable  strata  of  considerable  thick- 
ness, and  when  at  last,  in  another  age,  these  strata,  through 
some  changes  in  the  surface  of  the  land,  become  covered 
with  strata  of  sand,  or  clay,  or  gravel  which  the  flow  of 
water  forms  over  them,  and  which  afterward  become  strata 
of  rock,  the  vegetable  strata  become  converted  into  beds 
of  coal,  with  all  the  heat  and  power  which  they  derived 
from  the  sun  still  stored  in  them ;  that  is  to  say,  they 
consist  of  carbon  and  hydrogen  which  has  been,  by  great 
force,  separated  from  oxygen,  and  which  still  have  a  great 
tendency  to  combine  with  it ;  and  they  do  this,  when  the 
conditions  are  right,  with  great  force  and  with  the  evolu- 
tion of  great  heat,  which  force  and  heat  are  precisely  the 
same  in  amount  that  the  sun  expended  in  forming  them." 


166  MISS    ALMIRA. 

Miss  Almira  was  greatly  interested  in  these  truths.  She 
was  well  qualified  to  understand  and  appreciate  them,  for 
in  her  mental  constitution,  as  we  often  find  to  be  the  case 
with  young  ladies  of  her  age,  were  combined  the  charac- 
teristics of  poetic  feeling  and  of  scientific  exactness  and 
precision.  In  other  words,  she  was  capable  of  both  think- 
ing clearly  and  feeling  deeply.  And  the  idea  of  such  a 
vast  process  as  that  of  the  treasures  of  heat  from  the  sun 
being  slowly  deposited,  year  after  year,  century  after  cen- 
tury, and  age  after  age,  until  the  vast  accumulations  of 
power  which  lie  stored  in  the  great  coal  deposits  of  En- 
gland and  America  were  formed,  and  of  their  lying  there 
stored  as  immense  magazines  of  power  for  thousands  and 
thousands,  and  even  perhaps  millions  of  years,  and  then 
of  the  ingenuity  of  man  in  finding  them  and  penetrating 
to  them  at  the  enormous  depths  at  which  they  lie,  and 
raising  them  to  the  surface,  and  bringing  out  the  stored 
force  and  using  it  to  do  all  his  heavy  work — to  grind  his 
corn,  to  weave  his  cloth,  to  heat  his  furnaces,  to  warm  his 
rooms,  and  transport  him  by  sea  and  by  land  all  over  the 
globe — filled  her  mind  writh  wonder  and  delight.  She  not 
only  saw  and  enjoyed  the  precision  and  beauty  of  the  sci- 
entific principles  involved,  but  her  heart  was  filled  with  an 
emotion  akin  to  awe  in  the  contemplation  of  the  inexpress- 
ible grandeur  of  such  a  process. 


DIFFERENCE   BETWEEN   TEMPEEATUEE    AND    HEAT.    169 


CHAPTER  XVH. 

MEASUREMENT    OF    HEAT. 

Miss  ALMIEA  could  perceive  and  understand  nice  scien- 
tific distinctions,  too,  when  they  were  pointed  out  to  her, 
as  well  as  feel  the  sentiment  of  poetic  grandeur  and  beauty. 
An  instance  of  this  occurred  in  the  course  of  the  conversa- 
tion which  took  place  at  the  time  referred  to  in  the  last 
chapter.  Lawrence  had  occasion  to  speak  of  the  differ- 
ence, in  a  scientific  point  of  view,  bet  ween  temperature  and 
heat.  He  said  that  every  pound  of  coal  of  the  same  qual- 
ity— that  is,  containing  the  same  amount  of  carbon  and  hy- 
drogen, would  give  out,  in  combustion,  the  same  amount 
of  heat,  or,  as  he  expressed  it,  the  same  number  of  units  of 
heat.  She  asked  him  what  he  meant,  exactly,  by  units  of 
heat.  He  replied  by  asking  her  if  she  had  ever  read  or 
heard  how  heat  was  measured.  She  said  by  the  thermom- 
eter, she  supposed. 

Lawrence  replied  that  the  thermometer  measured,  or, 
rather,  indicated  heat  in  a  certain  popular  sense,  but  that, , 
strictly  speaking,  the  thermometer  only  made  known  the 
temperature  of  a  substance ;  and  that  by  the  temperature 
of  a  substance  was  meant  its  state  or  condition  in  respect 
to  its  power  of  communicating  heat  to  other  bodies,  and 
had  no  necessary  reference  to  the  quantity  of  heat  which 
it  really  itself  contained. 

This  is  a  very  important  scientific  distinction,  and  one 
which  a  great  many  persons,  even  better  informed  than 
Miss  Almira  was,  do  not  understand.  It  is  somewhat  dif- 
ficult to  understand  this  distinction — indeed,  almost  impos- 

H 


170  MEASUREMENT    OF   HEAT. 

sible  to  do  so  unless  the  mind  is  endued  with  something  of 
that  capacity  for  precise  and  exact  thought  which  Miss  Al- 
mira  possessed. 

You  can,  however,  begin  to  make  a  separation  of  the  two 
ideas  in  your  mind  by  considering  that  there  must  be  twice 
as  much  heat  in  respect  to  quantity,  in  two  gallons  of  boil- 
ing water,  as  there  is  in  one;  and  yet  the  temperature 
of  two  gallons  boiling  is  the  same  as  the  temperature  of 
one.  This  shows  that  the  expressions  temperature  and 
quantity  of  heat  stand  in  our  minds  for  two  very  different 
things. 

Temperature  is  the  condition  of  any  substance  in  respect 
to  its  tendency  to  impart  heat  to  surrounding  bodies.  When 
the  temperature  of  a  body  is  low  compared  with  that  of 
other  bodies  around  it,  as,  for  instance,  in  the  case  of  ice, 
in  an  open  summer  air,  or  in  a  glass  of  water,  we  may  re- 
gard it  as  having,  in  a  certain  sense,  the  same  disposition 
to  part  with  its  heat  as  it  has  when  surrounded  by  a  me- 
dium much  colder  than  itself,  as,  for  instance,  where  ice  at 
32°  is  surrounded  by  an  atmosphere  at  zero;  but  this  dis- 
position, or  tendency,  is  in  the  former  case  overborne  by 
the  superior  temperature — that  is,  the  superior  tendency 
to  part  with  heat — of  the-  air  or  water  surrounding  it. 

Thus  the  measure  of  the  temperature  of  a  substance  is 
only  the  measure  of  its  tendency  to  receive  or  impart  heat 
as  compared  with  other  bodies.  It  does  not  determine  at 
all  what  quantity  of  heat  the  substance  in  question  has  re- 
ceived in  bringing  it  to  that  condition;  for  it  may  be 
larger  or  smaller,  and  so  may  have  a  greater  or  less  quan- 
tity to  part  with,  or  it  may  have  imbibed  a  great  quantity 
which  remains  latent  in  it — that  is,  which  is  in  such  a  con- 
dition that  it  has  no  tendency  to  part  with  it.  We  meas- 
ure temperature  by  thermometers;  but  as  to  the  actual 
quantity  of  heat  which  any  substance  has  received  to  bring 


UNITS   OF  MEASUREMENT.  1*71 

it  up  to  any  particular  temperature,  that  is  a  very  different 
question,  and  must  be  determined  in  other  ways. 

In  order  to  impress  more  fully  on  Almira's  mind  the  dif- 
ference between  the  ideas  of  temperature  and  quantity  of 
heat,  Lawrence  varied  his  illustration  of  two  gallons  and 
one  gallon  of  water  by  referring  to  the  great  smoke-pipes 
which  ascend  from  the  furnaces  through  the  decks,  and 
which  the  passengers  were  so  much  in  the  habit  of  warm- 
ing themselves  by  in  cold  and  chilly  days. 

"  I  suppose,"  said  he, "  that  those  chimneys  are  about  as 
hot  as  common  iron  stoves  are  made  in  warming  a  room, 
for  they  are  not  red-hot,  and  they  are  too  hot  to  touch  with 
the  hand.  A  thermometer,  therefore,  would  indicate  the 
same  temperature  for  the  smoke-pipe  and  for  the  stove; 
but  the  quantity  of  heat  that  the  smoke-pipes  give  out 
must  be  enormously  greater  than  could  come  from  any 
stove,  on  account  of  their  enormously  greater  size." 

"  I  see  that,"  said  Almira,  "  but  I  don't  see  how  that 
quantity  can  be  measured." 

"  That  is  a  great  difficulty,"  said  Lawrence, "  and  for  a 
long  time  it  seemed  to  be  an  insurmountable  one.  There 
was  a  double  difficulty,  in  fact.  First  there  was  no  unit 
of  measurement  to  apply,  and,  in  the  second  place,  there 
seemed  to  be  no  means  of  applying  it  if  there  were  one." 

Lawrence  then  went  on  to  explain  that  in  all  measures 
there  must  be  a  unit  of  measurement,  as  it  is  called,  which 
is  a  certain  convenient  quantity  of  the  substance  to  be 
measured,  assumed  for  the  purpose.  Thus,  in  the  measure- 
ment of  lines,  a  foot  is  the  usual  unit  of  measurement  for 
certain  magnitudes,  and  a  yard,  a  mile,  or  an  inch  for  oth- 
ers ;  so  an  hour,  a  month,  or  a  year  are  units  of  measure- 
ment for  time. 

Now  we  have  names  for  all  these  units,  and  that  helps 
to  make  them  seem  very  simple,  for  giving  a  thing  a  dis- 


172  MEASUREMENT    OF    HEAT. 

tinct  name  has  a  wonderful  effect  in  simplifying  the  con- 
ception of  it  to  our  minds.  If  we  had  no  name  for  a  foot, 
but  were  obliged  to  designate  it  as  a  unit  of  measurement 
for  length,  denoting  a  quantity  equal  to  the  distance  from 
the  heel  to  the  toe  of  a  full-sized  man,  and  none  for  fathom, 
but  were  obliged  to  describe  it  as  a  unit  of  measurement 
for  depth  determined  by  the  portion  of  a  sounding-line 
which  a  man  can  draw  up  at  one  reach  between  his  two 
arms,  we  should  see  at  once  how  arbitrary  those  units 
would  be ;  and  it  would,  moreover,  be  much  more  difficult 
to  think  and  reason  about  them  than  it  is  at  present. 

Now,  in  respect  to  the  measurement  of  quantities  of  heat, 
it  is  necessary,  in  the  same  way,  to  take  some  arbitrary 
quantity  of  it,  as  a  unit,  to  measure  by.  For  instance,  we 
place  a  large  caldron  over  a  fire ;  a  certain  quantity  of 
heat  passes  up  every  minute,  through  the  iron,  into  the 
caldron.  This  quantity  may  be  measured.  It  may  be 
very  difficult  to  measure  it  in  some  cases,  just  as  it  is  very 
difficult  sometimes  to  measure  the  exact  length  of  a  line 
running  over  a  very  rough  or  very  marshy  piece  of  ground. 
But  we  can  conceive  of  its  being  measured — the  quantity 
necessary  to  raise  the  temperature  of  one  pound  of  water 
one  degree  being  taken  as  a  standard. 

It  is  plain,  moreover,  that  putting  a  thermometer  into  a 
substance,  whatever  it  may  be,  that  is  in  the  caldron,  will 
not  answer  at  all  as  a  means  of  making  this  measurement. 
The  thermometer,  in  such  a  case,  would  show  how  hot  the 
substance  had  become  at  the  time  of  applying  it,  but  it 
would  not  show  at  all  what  quantity  of  heat  had  passed  up 
through  the  iron  in  each  minute  to  make  it  so  hot.  It 
would  not  necessarily  enable  us  to  determine  this  if  we 
knew  how  hot  the  substance  that  the  kettle  contained  was 
at  the  commencement  of  the  experiment ;  for  the  increase 
of  temperature  in  the  contents  of  the  kettle,  though  it 


173 

would  depend  a  great  deal  on  the  amount  of  heat  coming 
into  it  from  the  fire,  would  not  depend  entirely  on  that,  but 
on  many  other  considerations,  such  as  what  the  substance 
was,  whether  water,  or  solid  ice,  or  oil,  and  many  other  cir- 
cumstances. 

Indeed,  we  can  scarcely  infer  at  all  what  quantity  of  heat 
any  substance  has  absorbed  from  its  temperature ;  for,  in 
the  first  place,  it  is  found,  curiously  enough,  that  some  sub- 
stances are  much  hotter — that  is,  their  temperature  is 
raised  much  higher  than  others  by  the  absorption  of  the 
same  amount  of  heat. 

And  then,  in  the  second  place,  there  are  cases  in  which  a 
very  large  amount  of  heat  may  be  communicated  to  a  sub- 
stance without  making  it  any  hotter — that  is,  the  heat  is 
expended  in  making  other  changes  in  its  constitution,  and 
does  not  raise  its  temperature  at  all. 

When  Lawrence  had  gone  as  far  as  this  in  his  explana- 
tion, he  found  that  Flippy  was  beginning  to  look  a  little 
tired,  for  such  general  explanations  were  a  little  too  ab- 
struse for  him,  and  so  he  thought  he  would  illustrate  the 
subject  by  a  kind  of  story. 

"  There  is  a  kind  of  an  experiment  that  you  can  perform 
yourself,  Flippy,"  said  he, "  to  make  this  very  clear.  I  will 
tell  you  how  some  boys  tried  it  who  were  not  afraid  of  the 
cold." 

"  I'm  not  afraid  of  the  cold,"  said  Flippy. 

"  Ah !  but  this  was  tremendously  cold,"  said  Lawrence. 
"  It  was  in  Vermont,  on  a  moonlight  night  in  January,  and 
the  thermometer  was  20°  below  zero." 

"  I  should  not  care  if  it  was  fifty  below  zero,"  said  Flippy. 

^It  is  sometimes  as  cold  as  that,  and  even  colder,"  said 
Lawrence, "  in  the  Arctic  regions ;  but  it  was  only  20°  be- 
low zero  when  these  boys  made  their  experiment.  They 
took  a  thermometer,  and  a  lantern,  and  an  iron  kettle,  and 


174  MEASUREMENT   OF   HEAT. 

went  down  to  a  small  pond  beyond  their  garden,  or,  rath- 
er, they  went  to  a  place  where  there  was  a  small  pond  in 
the  summer;  but  now  it  was  frozen,  over  two  feet  thick, 
and  covered  with  snow  two  feet  deep.  They  waited  a  few 
minutes  for  the  thermometer  to  get  cold,  and  then  looked 
at  the  mercury,  and  found  that  it  was  20°  below  zero. 
Then  they  filled  their  kettle  with  snow,  and  put  the  ther- 
mometer into  that,  and,  after  leaving  it  there  a  few  min- 
utes more,  they  looked  again,  and  found  that  the  mercury 
stood  at  eighteen  degrees  below  zero.  They  thus  ascer- 
tained that  the  snow  was  not  quite  so  cold  as  the  open  air. 
They  then  returned  toward  the  house,  bringing  the  ket- 
tle full  of  snow  with  them.  They  left  it  in  the  back  kitch- 
en, and  then,  after  putting  away  their  lantern  and  taking 
off  their  coats,  they  went  into  the  parlor  and  sat  down  to 
their  reading." 

Flippy  seemed  much  interested  in  listening  to  the  story, 
but  said  he  did  not  see  what  the  boys  did  all  that  for. 

"You'll  see  presently,"  said  Lawrence.  "  There  had  been 
no  fire  in  the  back  kitchen  where  the  boys  left  their  kettle 
of  snow,  and  so  it  was  very  cold  there ;  but  it  was  not 
nearly  so  cold  as  it  was  on  the  pond.  It  was  only  2°  be- 
low zero  there.  So,  while  the  snow  was  at  20°  below,  the 
air  in  the  room  was  only  2°  below,  and,  of  course,  the  snow 
began  to  grow  warmer." 

"  Warmer,"  repeated  Flippy ;  "  snow  can't  be  warm  at 
all." 

"  Well,  less  cold,  then,"  said  Lawrence.  "  When  any 
thing  is  less  cold,  we  call  it  warmer  in  science,  but  it 
means  the  same  thing.  To  make  it  less  cold,  it  had  to  re- 
ceive a  certain  quantity  of  heat  from  the  air  in  the  room. 
This  the  boys  found  to  be  the  fact,  for  they  came  out  into 
the  back  kitchen  in  about  half  an  hour,  and  tried  their 
thermometer  in  the  snow  again.  They  found  that  the 


SNOW    ON  THE    STOVE.  175 

snow  had  received  a  quantity  of  heat  from  the  air  in  the 
room  sufficient  to  raise  its  temperature  to  4°  below  zero 
— nearly,  but  not  quite,  up  to  the  temperature  of  the  air  in 
the  back  kitchen. 

"Then  they  carried  the  kettle  of  snow  into  the  front 
kitchen,  and  put  it  on  the  stove.  It  was  now  in  a  condi- 
tion to  receive  heat  much  faster  than  before,  for  there  was 
a  fire  in  the  stove,  and,  when  the  kettle  was  put  in  its 
place,  the  bottom  of  it  came  almost  in  contact  with  the 
fire.  The  boys  left  their  snow  in  this  position  for  about 
eighteen  minutes,  and  then,  trying  their  thermometer  in  it 
again,  they  found  that  it  had  risen  to  32°  above  zero.  Thus, 
inasmuch  as  it  was  4°  below  zero  when  they  brought  it  in, 
it  had  received  a  quantity  of  heat  from  the  fire  sufficient  to 
raise  the  temperature  about  thirty-six  degrees.  The  snow 
was,  in  fact,  beginning  to  melt  quite  fast. 

"  The  boys  then  went  away  again  and  remained  half  an 
hour,  leaving  the  kettle  with  the  snow  in  it  over  the  fire. 
After  they  had  waited  for  half  an  hour,  they  came  back. 
They  found  that  the  snow  was  now  nearly  all  melted ;  but 
when  they  put  the  thermometer  in,  to  try  the  temperature, 
they  found  that  it  was  still  32° — just  what  it  was  before ! — 
that  is,  although  the  fire  in  a  quarter  of  an  hour  had  raised 
the  temperature  of  the  solid  snow  thirty-six  degrees,  yet  in 
half  an  hour,  though  there  was  the  same  fire,  and  the  same 
quantity  of  heat  going  in  all  the  time  through  the  bottom 
of  the  kettle,  the  temperature  had  not  been  raised  at  all. 

"  This  was  wonderful  to  them.  They  had  read  that  it 
would  be  so  in  their  books,  and  they  had  tried  this  exper- 
iment to  test  the  question.  It  seemed  to  them  very  singu- 
lar that  all  that  quantity  of  heat  passing  up  into  the  melt- 
ing snow  should  not  warm  it — that  is,  should  not  raise  the 
temperature  at  all. 

"  The  explanation  is,  that  all  this  quantity  of  heat,  which 


176  MEASUREMENT    OF    HEAT. 

was  enough  to  have  raised  the  temperature  of  water  a  great 
many  degrees  —  high  enough,  in  fact,  to  make  it  scalding 
hot,  if  it  had  been  able  to  employ  itself  for  that  purpose — 
was  really  employed  in  changing  ice  into  water,  for  snow 
is  only  ice  in  thin  flakes ;  that  is  to  say,  it  was  employed 
in  making  a  change  in  the  internal  constitution  of  the  sub- 
stance, and  not  in  raising  its  temperature. 

"The  boys  left  their  kettle  of  water  again  and  went  back 
to  their  reading ;  the  thermometer  indicated  32°.  But 
when  they  left  the  kettle  this  time  the  ice  was  all  melted, 
and  thus  the  heat,  having  now  no  more  work  to  do  in 
changing  the  internal  constitution  of  the  substance,  could 
expend  its  force  in  raising  the  temperature  of  it,  and  it  be- 
gan to  grow  hotter  very  fast.  In  fact,  when  the  boys  came 
back,  half  an  hour  later,  the  water  was  boiling — that  is,  the 
temperature  of  it  had  been  raised  to  212°." 

"Then  they  must  have  spoiled  their  thermometer  in 
putting  it  in,"  said  Flippy. 

"  Oh  no,"  said  Lawrence  ;  "  they  had  a  kind  of  thermom- 
eter which  the  chemists  use.  The  scale  turns  back  out  of 
the  way  when  you  wish  to  put  it  into  snow  or  water." 

"Is  that  story  true?"  asked  Flippy,  after  a  moment's 
pause. 

"  No,"  replied  Lawrence,  coolly. 

"  Then  you  made  it  up,"  said  Flippy. 

"  Yes,"  said  Lawrence,  "  in  order  to  let  you  see  clearly, 
and  have  fixed  in  your  mind,  the  distinction  between  the 
idea  of  temperature  and  that  of  quantity  of  heat,  and  un- 
derstand that  a  thermometer,  though  it  may  measure  one 
very  correctly,  tells  us  nothing  at  all  about  the  other." 

"  It  helps  me  to  understand  it  very  much,"  said  Almira. 
"Indeed,  I  never  understood  it  at  all  before.  I  always  im- 
agined that,  somehow  or  other,  the  thermometer  measured 
the  quantity  of  heat." 


WHAT   IS   THE    UNIT    OF    HEAT?  177 

"  I  understand  it  pretty  well  myself,"  said  Flippy,  "  but 
I  would  rather  that  the  story  should  have  been  true." 

"  You  can  make  it  true,"  said  Lawrence,  "  by  trying  the 
experiment  yourself  some  time  next  winter." 

"  I  mean  to  do  it,"  said  Flippy,  "  if  I  can  only  get  that 
kind  of  thermometer." 

Lawrence  went  on  to  state  again,  as  he  had  done  once 
before,  that  in  measuring  and  noting  quantities  of  heat,  it 
was  necessary  to  assume  some  particular  quantity  as  the 
measuring  unit.  The  unit  used  for  this  purpose  in  English- 
speaking  nations  is  the  amount  required  to  raise  the  temper- 
ature of  one  pound  of  water  one  degree  of  Fahrenheit  s  ther- 
mometer. This  is  called  the  English  unit  of  heat. 

I  advise  all  the  readers  of  this  book  to  fix  this  very  firm- 
ly in  their  minds,  namely : 

The  English  unit  of  heat  is  that  quantity  of  heat  which  is 
expended  in  raising  the  temperature  of  one  pound  of  water 
one  degree. 

The  French,  who  have  a  different  standard  of  weight  and 
a  different  thermometer  from  ours,  have  a  unit  of  heat  on 
the  same  principle,  though  adapted  to  their  measures.  It 
is  the  quantity  expended  in  raising  one  kilogramme  of  wa- 
ter one  degree  of  the  Centigrade  thermometer.  They  call 
their  unit  of  heat  a  calorie.  We,  the  English-speaking 
people,  have  no  name  for  ours ;  we  call  it  simply  the  unit 
of  heat. 

Thus,  if  we  were  to  put  a  red-hot  iron  ball  into  a  pail 
which  contained  ten  pounds  of  water,  and,  after  letting  it 
remain  until  it  was  as  cool  as  the  water,  if  it  should  then 
be  found  that  the  water  was  made  three  degrees  warmer 
by  it,  then  there  would  have  passed  from  the  ball  thirty 
units  of  heat,  for  ten  pounds  of  water  would  have  been 
raised  three  degrees  each,  which  makes  thirty. 

It  makes  no  difference  how  warm  or  how  cold  the  water 
H2 


1*78  MEASUREMENT    OF   HEAT. 

was  at  the  commencement,  for  it  is  found,  by  means  of  very 
curious  experiments,  that  within  a  very  wide  range  of  units 
it  requires  practically  the  same  quantity  of  heat  to  raise 
the  temperature  of  water  one  degree,  whatever  its  temper- 
ature may  have  been  before. 

So  the  way  to  determine  how  much  heat  is  given  out  by 
a  lamp  burning  an  hour  is  to  contrive  some  way  to  find 
out  how  many  degrees  it  will  warm  a  given  quantity  of 
water. 

"I  do  not  see  how  they  can  do  it,"  said  Almira,  when 
Lawrence  had  made  this  explanation ;  "  for  I  don't  see 
how  they  can  manage  to  make  all  the  heat  from  a  candle, 
for  example,  or  from  any  other  fire,  go  into  the  water. 
Some  of  it  would  escape  in  other  ways." 

"  They  arrange  it  so  that  there  shall  be  water  all  around 
it,"  said  Lawrence.  "  Of  course  they  have  to  contrive  a 
special  apparatus  for  the  purpose,  so  that  what  is  to  be 
burned  shall  be  inclosed  in  water,  and  the  pipe  by  which 
all  the  products  of  combustion  pass  away  shall  make  a 
circuit  in  the  water  till  the  gases  and  fumes  are  entirely 
cool. 

"  But  another  still  more  curious  way,"  he  added,  "  to 
find  out  how  much  heat  is  produced  by  the  combustion  of 
a  given  substance  is  to  burn  it  inclosed  in  ice.  They  make 
a  vessel  of  sheet-iron,  the  sides  of  which  are  double,  with 
quite  a  space  between.  Inside  the  inner  vessel  they  have 
something  to  hold  the  substance  which  they  wish  to  burn, 
and  put  all  around  this  a  quantity  of  pounded  ice,  so  as  to 
fill  all  the  space  in  the  inner  vessel  not  occupied  by  the  re- 
ceptacle for  the  fuel  and  the  air-passages  communicating 
with  it. 

"  They  also  fill  all  the  space  between  the  double  wall  of 
the  vessel  with  ice.  Of  course  there  is  an  opening  below 
to  admit  air  to  the  fire,  and  a  pipe  above  to  allow  the  gases 


LAWRENCE'S  DRAWING. 


179 


QUANTITY   OF  HEAT. 


to  escape,  after  they  have  been  carried  round  and  round  in 
a  spiral  pipe  till  they  have  become  cool. 

"  In  this  way  all  the  heat  which  is  produced  by  the  com- 
bustion is  spent  in  melting  the  ice. 
The  water  that  is  thus  produced  is 
drawn  off  afterward  by  a  pipe  and 
faucet  below,  as  you  see  in  the  en- 
graving. They  weigh  this  water, 
and  so  find  out  how  much  ice  the 
heat  produced  by  that  burning  has 
liquefied ;  but  to  melt  ice,  as  has  been 
found  out  in  other  ways,  requires  140 
units  of  heat — that  is,  it  requires  as 
much  heat  to  melt  one  pound  of  ice 
as  it  would  to  raise  the  temperature 
of  the  same  weight  of  water  140  de- 
grees, or  to  raise  the  temperature  of 
140  pounds  of  water  one  degree.  So,  from  the  quantity 
of  water  which  they  get  by  the  faucet  in  the  apparatus 
above  described,  they  can  tell  by  an  easy  calculation  how 
many  units  of  heat — that  is,  what  quantity — was  produced 
by  this  combustion." 

As  Lawrence  said  this,  he  drew  a  small  portfolio  out  of 
his  pocket,  and  made  a  little  drawing  upon  a  piece  of  paper 
which  he  took  from  it,  to  show  the  party  the  form  of  the 
apparatus  which  he  had  described. 

Almira  and  the  boys  were  all  quite  interested  in  looking 
at  the  drawing,  and  Almira  asked  Lawrence  if  he  would 
allow  her  to  keep  it. 

"  No,"  said  Flippy,  "_Z"  want  it — to  put  into  my  jour- 
nal." 

"Very  well,"  said  Lawrence;  "Flippy  may  have  this 
one,  and  I  will  make  for  you  another,  Miss  Almira,  and  will 
give  it  to  you  to-morrow. 


180  MEASUREMENT    OF    HEAT. 

"  Only  remember,  boys,"  he  added,  "  what  the  purpose 
is  which  it  is  intended  to  effect,  namely,  to  determine  what 
quantity  of  heat  is  developed  in  any  particular  process  of 
combustion,  by  showing  how  much  ice  it  will  melt,  there 
being  140  units  of  heat  required  for  every  pound  of  water 
produced  by  the  melting." 


A    RECAPITULATION.  181 


CHAPTER  XYIH. 

PERSONALITIES. 

LAWRENCE  gave  Flippy  the  little  drawing,  and  then  said 
that  he  had  talked  long  enough — too  long,  he  was  afraid — 
and  so  they  would  go  up  on  deck  and  see  what  was  to  be 
seen  there. 

But,  before  we  let  them  go,  let  me  giv^  you  a  recapitula- 
tion of  what  he  had  explained  to  them,  so  that  you  may 
have  it  well  fixed  in  your  minds.  It  was  this :  The  ther- 
mometer does  not  measure  quantities  of  heat  at  all.  It 
only  shows  to  what  condition,  as  to  heat,  any  substance 
has  reached ;  it  tells  us  nothing  about  the  quantity  of  heat 
which  it  has  received  to  bring  it  to  that  condition.  These 
quantities  are  estimated  in  what  are  called  units  of  heat, 
the  English  unit  being  the  amount  necessary  to  raise  the 
temperature  of  one  pound  of  water  one  degree. 

You  must  remember,  too,  that  the  quantity  of  heat  which 
can  be  produced  by  burning  any  particular  amount  of  any 
kind  of  combustible  is  fixed,  and  can  not  be  increased  or 
diminished.  The  reason  is,  that  it  contains  only  a  certain 
quantity  of  carbon  and  hydrogen,  and  that  that  quantity 
of  carbon  and  hydrogen  can  only  combine  with  a  certain 
fixed  quantity  of  oxygen,  and  that,  in  so  combining,  can 
only  give  out  a  certain  fixed  amount  of  heat.  You  can 
make  it  give  this  quantity  out  faster  or  slower  by  blowing 
or  not  blowing  the  fire — that  is,  by  supplying  it  with  oxy- 
gen more  or  less  rapidly.  Thus  you  can  get  a  heat  more 
intense  in  degree  by  increasing  the  rapidity  of  the  combus- 
tion, and  so  shortening  the  time.  In  other  words,  you  can 


1 82  PERSONALITIES. 

raise  the  temperature  for  a  time,  but  you  can  not  increase 
the  total  quantity  of  heat  that  the  combustion  will  pro- 
duce. 

It  is  necessary  that  the  reader  should  clearly  understand 
this  last  point,  not  only  because  it  involves  a  fundamental 
principle  in  the  science  of  heat,  but  also  it  is  necessary  to 
enable  him  clearly  to  comprehend  a  conversation  which 
subsequently  took  place  between  Flippy  and  his  mother, 
as  will  be  related  in  due  time. 

When  Lawrence  had  finished  the  conversation  related  in 
the  last  chapter,  Almira  thanked  him  for  the  information 
which  he  had.  given  her,  and  asked  him  if  he  was  willing, 
the  next  time  he  had  a  conversation  with  the  boys  on  such 
subjects,  to  allow  her  to  be  present  too.  To  this  request 
Lawrence  readily  acceded.  Indeed,  he  was  much  pleased 
to  find  that  Miss  Almira  took  an  interest  in  such  investi- 
gations. 

So  Lawrence  and  the  boys  went  on  deck,  while  Almira 
took  out  her  journal  to  write  an  account  in  it  of  the  con- 
versation which  she  had  had  with  Lawrence,  and  to  make 
a  brief  summary  of  the  principles  which  he  had  explained, 
in  order  to  fix  them  in  her  mind.  She  left  a  place  on  the 
page  to  gum  in  the  little  drawing  which  Lawrence  had 
promised  to  make  for  her,  to  illustrate  the  manner  in  which 
quantities  of  heat  could  be  measured  by  the  quantity  of  ice 
melted,  at  the  rate  of  140  units  to  the  pound. 

Lawrence  and  the  boys  went  on  deck.  They  walked 
forward  and  looked  all  around  to  see  whether  there  were 
any  sails,  or  steamers,  or  icebergs  in  sight. 

"I  wish  we  could  see  an  iceberg,"  said  Flippy.  "My 
mother  says  she  wants  to  see  one  very  much." 

There  was,  however,  nothing  to  be  seen.  Accordingly, 
after  looking  about  for  a  little  time,  they  all  three  sat  down 
upon  a  large  cushioned  sofa  which  was  placed  against  the 


HEAD    AND    HEART.  183 

paddle-box.  There  were  a  great  many  other  people  sit- 
ting in  different  places  on  the  decks,  some  upon  folding 
chairs,  and  some  upon  camp-stools,  while  others  were  walk- 
ing back  and  forth  along  the  decks  for  exercise. 

"  We've  got  another  member  of  our  class,"  said  John. 

"  Yes,"  said  Lawrence, "  and  I'm  very  glad  of  it." 

"I'm  glad  too,"  said  John;  "but  what  is  her  other 
name  besides  Almira  ?" 

"  I  don't  know,"  replied  Lawrence ;  "  I  did  not  hear  her 
other  name." 

"  How  do  you  like  her  ?"  asked  John. 

"  I  like  her  very  much,"  replied  Lawrence.  "  She  has 
mind  and  soul  both." 

"  What  do  you  mean  by  that  ?"  asked  Flippy. 

"  Why,  that  she  has  both  head  and  heart ;  and  that  is 
not  true  of  every  girl." 

"  I  don't  know  about  heart,"  said  Flippy, "  but  I  never 
saw  any  girl  without  any  head." 

John  laughed,  and  then  asked  Lawrence  if  he  knew 
where  Miss  Almira  was  from.  He  said  no,  but  he  thought 
she  was  from  somewhere  in  the  interior  of  the  country. 
John  said  he  did  not  think  she  looked  like  a  country  girl 
at  all.  Lawrence  replied  that  if  he  meant  by  that  to  say 
that  she  had  the  appearance  and  manners  of  a  lady,  he 
agreed  with  him  entirely. 

"  She  has  evidently  been  accustomed,"  he  said,  "  to  cul- 
tivated and  refined  society,  but  she  does  not  appear  like 
the  girls  who  have  spent  all  their  lives  in  the  great  cities, 
where  they  pass  their  time  in  such  a  continual  whirl  of  ex- 
citement and  pleasure,  poor  things !  that  they  have  no  time 
to  acquire  habits  of  quiet  reflection.  They  are  very  bril- 
liant, and  are  charming  sometimes  in  light  conversation. 
They  are  very  intelligent,  too,  in  their  way.  But  they  are 
not  generally  so  thoughtful  and  considerate  as  the  country 


1 84  PEESONALITIES. 

girls,  and  do  not  listen  so  calmly  and  quietly  to  what  they 
hear.  They  half  hear  it,  and  then  away  their  thoughts  fly 
to  something  else." 

I  think  myself  that  Lawrence  was  somewhat  too  sweep- 
ing in  the  expression  of  his  opinion  of  the  comparative  in- 
tellectual characteristics  and  habits  of  thought  of  city  and 
country  girls,  though  there  may  be  some  ground  for  the 
distinction  which  he  made,  inasmuch  as  those  who  are 
brought  up  in  the  country  are  much  more  alone,  and  have 
much  more  time  and  opportunity  for  quiet  reflection  than 
those  who  spend  their  lives  amidst  the  constant  bustle  and 
excitement  of  great  cities ;  and  it  is  very  natural  to  sup- 
pose that  these  differences  in  the  influences  operating  upon 
them  respectively  should,  in  many  cases,  produce  a  differ- 
ence of  result. 

The  next  evening  after  this,  when  Lawrence  went  to  his 
state-room  to  go  to  bed,  a  little  while  after  John  had  re- 
tired— for  there  was  not  room  in  the  state-room  for  them 
both  to  undress  together — John  looked  down  from  his 
berth,  which  was  the  upper  one,  and  said, 

"  Are  you  going  to  turn  in,  Lawrence  ?" 

The  phrase  for  going  to  bed  at  sea  is  "  turning  in."  It 
is  turning  in,  literally,  for,  in  order  to  get  into  your  berth, 
you  have  to  put  your  head  in  first,  and  then  give  a  pecul- 
iar kind  of  roll  over,  which  could  not  be  so  well  described 
by  any  other  words  as  by  "  turning  in." 

"  Yes,"  said  Lawrence ;  "  it  is  about  time." 

"  I'm  sorry  I've  turned  in,"  said  John. 

"  Why  ?"  asked  Lawrence. 

"  Because  I'm  not  sleepy,"  said  John ;  "  I  could  not  go 
to  sleep  if  I  were  to  try." 

"  It  takes  a  wise  man,  and  a  still  wiser  boy,"  said  Law- 
rence, "to  tell  when  he  can  and  when  he  can  not  go  to 
sleep.  Lie  down  and  shut  your  eyes,  and  very  likely  you'll 
be  asleep  before  you  know  it." 


REPEATING    UNCOMPLIMENTARY    REMARKS.  185 

John  lay  down  for  a  moment,  while  Lawrence  continued 
his  preparations  for  going  to  bed ;  but  soon  he  raised  his 
head  again  and  said,  » 

"  I  think  it  likely  that  Almira  may  like  you  well  enough, 
but  I  don't  believe  that  Mrs.  Gray  does." 

"  What  makes  you  think  so  ?"  asked  Lawrence. 

"  Because  Flippy  told  me  that  she  said  she  thought  you 
was  a  pedantic  boor." 

"A  pedantic  boor!"  repeated  Lawrence.  "That's  ex- 
pressive, at  any  rate.  I'm  glad  you  told  me  that  that's 
the  opinion  she  has  formed  of  me.  I'll  see  if  I  can't  make 
her  change  it." 

"  How  will  you  do  it  ?"  asked  John.  "  If  I  were  you,  I 
would  not  speak  to  her  all  the  voyage." 

"  I'll  try  a  better  way  than  that,"  said  Lawrence. 

"  What  is  your  way  ?"  asked  John. 

"  I'll  wait  till  I've  tried  it,"  said  Lawrence,  "before  I  tell 
you  what  it  is.  If  I  succeed,  then  I'll  tell  you  all  about  it." 

Now,  although  Lawrence  said  that  he  was  glad  to  hear 
what  Mrs.  Gray  had  said  of  him,  it  was  a  mistake  of  judg- 
ment on  John's  part  to  repeat  it  to  him ;  for  it  is  a  gen- 
eral, indeed  an  almost  universal  rule  that  we  ought  not  to 
report  to  our  friends  any  evil  that  we  may  have  acciden- 
tally learned  to  have  been  said  of  them  by  other  people, 
as  it  only  tends  to  vex  and  irritate  them,  and  to  increase 
and  perhaps  perpetuate  an  alienation  and  ill  feeling  which 
might  otherwise  have  been  only  momentary.  Generally, 
when  people  hear  such  things,  it  awakens  resentment  and 
anger,  and  leads  to  a  retaliation  which  only  makes  the 
matter  worse. 

But  Lawrence  had  taken  great  interest  in  studying  the 
movements  and  operations  of  the  human  mind,  as  well  as 
those  of  the  forces  of  external  nature,  and  he  knew  very 
well  that  such  expressions  as  Mrs.  Gray  had  applied  to 


186  PERSONALITIES. 

him,  and  the  feelings  which  prompted  them,  often  arose, 
in  the  case  of  such  persons  as  Mrs.  Gray,  from  the  most 
frivolous  and  insignificant  causes.  He  had  no  doubt  that 
Mrs.  Gray's  expressing  herself  so  unfavorably  arose  from 
some  accidental  impression  made  by  what  he  had  said  or 
done  on  some  occasion,  and  that  the  way  to  remove  that 
impression  was  for  him  to  seek  some  opportunity  of  mak- 
ing another  and  better  one.  He  took  great  pleasure  in  the 
idea  of  attempting  to  do  this  by  the  appropriate  means,  as 
an  experiment  upon  mind — an  experiment  of  a  kind  much 
more  interesting  than  those  made  upon  matter,  on  account 
of  the  greater  delicacy  of  the  "  forces,"  as  he  called  them, 
with  which  he  had  to  deal. 

The  circumstances  under  which  Mrs.  Gray  had  called 
Lawrence  a  pedantic  boor  were  these :  On  the  evening  be- 
fore the  conversation  between  Lawrence  and  John  in  their 
state-room,  as  above  described,  Flippy  went  to  a  part  of 
the  saloon  where  his  mother  was  sitting  with  another  lady, 
doing  some  kind  of  crochet- work. 

"  Well,  Flippy,"  said  his  mother,  "  it  is  about  time  for 
you  to  go  below  and  go  to  bed.  Have  you  had  a  pretty 
good  time  to-day  ?" 

Flippy  said  he  had  had  a  very  good  time. 

"I  see  you  have  been  talking  with  Mr.  Wollaston  a  good 
deal  to-day.  He  does  not  take  any  notice  of  me  whatever. 
I  think  he  is  very  rude." 

Flippy  said  he  did  not  think  he  was  rude  at  all. 

"Oh  no  !"  said  Mrs.  Gray.  "I  dare  say  he  has  been  very 
polite  to  you.  And  what  new  philosophical  nonsense  has 
he  been  teaching  you  to-day  ?" 

"  No  nonsense  at  all,"  said  Flippy ;  "  but  he  has  taught 
me  something  that  I  never  knew  before,  and  that  is,  that 
there  is  only  so  much  heat  to  be  got  out  of  a  pound  of 
coal,  no  matter  how  you  burn  it." 


MRS.  GRAY'S  OPINION.  187 

"  Well,  I'm  sure  that  is  nonsense,"  replied  Mrs.  Gray,  "  if 
there  is  any  such  thing.  All  the  world  knows  that  you 
may  make  the  same  fire  a  great  deal  hotter  by  blowing  it 
with  the  bellows.  Any  blacksmith's  boy  could  tell  him 
that." 

"  Yes,  mother,"  said  Flippy,  "  the  fire  is  hotter  for  the 
time,  but  there  is  no  more  heat,  in  all,  to  come  out  of  it." 

"  Nonsense,  Flippy !"  said  his  mother.  "  To  say  that  it 
is  hotter  is  only  another  way  of  saying  there  is  more  heat. 
I  think  your  Mr.  Lawrence,  as  you  call  him,  is  a  pedantic 
boor."  So  saying,  she  turned  to  the  lady  sitting  by  her 
side,  and  said,  "Just  hear,  Caroline.  There  is  a  young  man 
who  pretends  to  be  a  great  philosopher,  and  he  says  you 
can't  make  a  fire  any  hotter  by  blowing  it  with  the  bel- 
lows !" 

Here  Mrs.  Gray  laughed  aloud,  and  the  other  lady  joined 
her. 

"  Was  there  ever  any  thing  so  absurd  ?"  said  she. 

Here  the  two  ladies  laughed  so  much  that  the  crochet- 
work  was  entirely  interrupted. 

Poor  Flippy,  as  might  have  been  expected,  was  silenced, 
but  not  convinced.  Indeed,  although  he  had  a  tolerably 
clear  idea,  for  such  a  boy,  of  the  distinction  between  the 
whole  quantity  of  heat  which  the  combustion  of  the  coal 
could  be  made  to  render,  and  the  intensity,  in  respect  to 
temperature,  to  which  the  combustion  could  be  urged  by 
hastening  the  rapidity  of  it,  he  could  not  explain  it  to  his 
mother  very  well,  and  so  he  wisely  gave  up  the  attempt. 
He  stood  silent  for  a  moment,  and  then  went  away,  and, 
by  way  of  relieving  his  indignant  feelings  in  some  slight 
degree  by  giving  them  utterance,  told  John  that  his  moth- 
er called  his  cousin  Lawrence  a  pedantic  boor. 

It  is  not  surprising  that  Flippy  had  not  learned  to  feel 
any  more  interest  in  the  cultivation  of  his  mind  and  the 


188  PERSONALITIES. 

acquisition  of  knowledge  if  he  had  been  accustomed  from 
infancy  to  receive  from  his  mother  so  little  help,  encour- 
agement, and  sympathy  as  this. 

Lawrence's  idea  that  Mrs.  Gray's  unfavorable  opinion,  in 
respect  to  his  gentlemanliness,  implied  in  her  calling  him  a 
boor,  was  derived  from  some  accidental  impression  made 
upon  her  mind,  which  might  very  likely  be  easily  removed, 
was  very  correct.  The  unfavorable  impression  arose  from 
the  fact  that,  while  he  had  been  comparatively  quite  inti- 
mate with  Flippy,  he  had  not  paid  any  attention  to  her, 
Flippy's  mother.  Now,  in  such  cases  as  this,  of  a  voyage 
at  sea,  where  persons  are  thrown  together  without  means 
of  regular  introductions  to  each  other,  it  requires  a  great 
deal  of  tact  and  judgment,  especially  on  the  part  of  young 
gentlemen,  to  draw  the  line  between  want  of  attention  on 
the  one  hand  and  intrusiveness  on  the  other.  A  gentle- 
man is  placed  at  the  table,  for  example,  next  a  lady  whom 
he  does  not  know,  and  is  to  sit  next  her  every  day  for  a 
week.  Shall  he  speak  to  her  ?  She  may  think,  if  he  does, 
that  he  is  forward  and  presuming.  Shall  he  take  no  notice 
of  her?  She  may  conclude  that  he  is  very  uncivil.  Almost 
every  gentleman,  under  such  circumstances,  often  finds  his 
situation  for  a  time  somewhat  embarrassing,  and,  with  the 
best  intentions  in  the  world,  and  the  most  sincere  desire  to 
do  what  will  be  most  agreeable  to  those  with  whom  he  is 
thus  thrown  into  association,  is  often  at  a  loss  what  to  do, 
and  is  exposed  to  be  unjustly  judged  by  ladies  who  do  not 
properly  consider  the  circumstances  of  the  case.  This  was 
Lawrence's  fate.  He  had  no  means  of  knowing  whether 
Mrs.  Gray  would  consider  him  entitled  to  speak  to  her  on 
the  ground  of  his  acquaintance  with  her  son,  or  would  con- 
sider it  an  act  of  presumption  on  his  part  to  do  so.  And 
she,  because  he  did  not  do  so,  pronounced  him  a  boor. 


AN   EXPERIMENT    ON   MIND.  189 


CHAPTER  XIX. 

THE    ICEBERG. 

THE  next  day  after  the  conversation  between  Lawrence 
and  John,  related  in  the  close  of  the  last  chapter,  while 
Lawrence  was  reading  in  a  folding  chair  under  the  lee  of 
the  mainmast,  John  came  to  tell  him  that  there  was  a  large 
iceberg  in  sight.  It  had  suddenly  come  into  view,  through 
an  opening  in  the  fog,  on  the  starboard  bow. 

Lawrence  immediately  rose  and  went  forward  to  see  it. 
He  found  that  a  number  of  passengers  were  assembled  on 
the  forward  deck,  and  were  scanning  the  iceberg  with  their 
glasses. 

"Ah !"  said  Lawrence  to  himself,  "here  is  an  opportunity 
for  me  to  make  my  experiment  on  mind." 

"  Flippy,"  said  he,  "  where  is  your  mother  ?" 

Flippy  said  that  he  believed  that  she  was  in  the  saloon. 

So  Lawrence  went  down  at  once  into  the  saloon,  and 
there  he  found  Mrs.  Gray  seated  by  the  side  of  Miss  Al- 
mira.  Mrs.  Gray  had  some  embroidery-work  in  her  hand, 
but  Miss  Almira  had  a  book  before  her.  They  seemed, 
however,  to  be  engaged  in  conversation  when  Lawrence 
went  in. 

Lawrence  bowed  recognition  to  Miss  Almira  as  he  ap- 
proached the  ladies,  and  then  accosted  Mrs.  Gray,  saying, 

"  Your  son  informed  me,  Mrs.  Gray,  that  you  had  a  great 
desire  to  see  an  iceberg,  and  there  is  one  coming  in  sight 
now.  I  thought  you  would  excuse  my  taking  the  liberty 
of  coming  to  inform  you." 

"  I  am  very  much  obliged  to  you,  indeed,  Mr.  Wollas- 
ton,"  said  Mrs.  Gray,  suddenly  rising. 


190  THE   ICEBERG. 

"  You  will  like  your  opera-glass,"  said  Lawrence  ;  "  per- 
haps it  is  better  than  mine.  Can  I  get  it  for  you  ?" 

Mrs.  Gray  said  that  her  glass  was  on  the  sofa,  in  her 
state-room ;  but  she  was  sorry  to  trouble  Mr.  Wollaston  to 
go  for  it.  He  said  he  could  go  in  a  moment.  He  knew 
where  the  state-room  was,  as  he  had  often  seen  Flippy  go 
in  and  out.  So,  after  saying  to  Miss  Almira  that  perhaps 
she  would  like  to  go  too,  he  went  down  for  the  glass,  and 
soon  returned,  meeting  the  two  ladies  at  the  door  of  the 
saloon. 

He  conducted  them  out  upon  the  main  deck,  and  thence 
up  the  flight  of  steps  which  led  to  the  promenade  deck 
above.  He  then  led  the  way  forward,  offering  his  arm  to 
Mrs.  Gray,  that  she  might  aid  her  in  steadying  her  steps  in 
walking  along  the  deck.  Miss  Almira  walked  by  herself 
at  Mrs.  Gray's  side. 

Lawrence  was  polite  and  attentive  to  Miss  Almira,  but 
he  devoted  his  chief  attention  to  Mrs.  Gray,  as  being  the 
elder  lady  of  the  two.  He  thought  that  if  Miss  Almira 
was  as  sensible  a  girl  as  he  had  supposed  her  to  be,  she 
would  understand  this,  and  would  not  feel  disturbed  by  it. 
Nor  was  he  mistaken  in  this  idea. 

They  soon  came  in  sight  of  the  iceberg,  which  was  very 
large,  and  of  a  very  grotesque  and  irregular  form.  This 
irregularity  was  caused  by  the  different  density  of  the  dif- 
ferent portions  of  it,  arising  from  the  .manner  in  which  it 
had  been  formed,  taken  in  connection  with  the  different  ac- 
tion of  the  sea  on  the  several  portions  of  it,  as  it  had  been 
beaten  and  washed  by  the  waves. 

There  is  something  very  curious,  and  also  very  grand  in 
the  history  of  these  icebergs.  They  are  formed,  in  the  first 
place,  in  a  very  wonderful  manner.  The  vapors  which  are 
brought  by  the  winds  from  the  tropical  regions  give  out 
their  heat  into  the  cold  air  of  the  arctic  regions,  and  fall  in 


HISTORY    OP   AN   ICEBERG.  193 

rain  and  snow  all  over  Greenland.  They  fall  all  over  the 
land,  and  there — as,  after  once  falling,  they  never  melt,  or, 
at  least,  only  do  so  occasionally  and  in  a  very  slight  degree 
— a  vast  bed  of  ice  is  formed,  which  increases  in  depth  year 
after  year  and  century  after  century,  until  it  forms  a  mass 
sometimes  thousands  of  feet  thick. 

There  would,  indeed,  apparently  be  no  end  to  this  accu- 
mulation in  thickness  were  it  not  that,  wonderful  as  it  may 
seem,  the  whole  mass  has  a  constant  onward  motion,  over 
the  sloping  surface  of  the  country,  toward  the  sea. 

Such  glaciers  always  have  this  slow  motion  where  the 
ground  on  which  they  form  is  inclined.  This  is  so  won- 
derful that  people  were  for  a  long  time  unwilling  to  be- 
lieve it  possible.  But  it  is  now  abundantly  proved  to  be 
true,  riot  only  in  respect  to  the  glaciers  of  Greenland,  which 
in  some  places  cover  the  whole  country,  but  in  Switzer- 
land and  the  Tyrol,  where  they  only  occupy  comparatively 
narrow  valleys. 

The  movement  is,  however,  very  slow,  from  a  few  inches 
only  to  a  few  feet  every  day,  according  to  the  state  of  the 
weather  and  the  slope  of  the  incline.  Thus  you  see  very 
easily  that  ice  formed  in  the  interior  of  the  country  might 
be  hundreds,  and  perhaps  thousands  of  years  in  reaching 
the  sea,  all  the  time  growing  in  thickness  as  it  moves  on. 
At  length,  as  the  advancing  front  of  it  reaches  the  margin 
of  the  shore,  it  can  not  stop,  but  is  forced  onward  by  the 
pressure  of  the  mass  behind  it,  until  it  gets  crowded  out 
over  the  water  far  enough  to  be  broken  off  in  immense  por- 
tions by  the  floatage  and  by  the  force  of  the  waves. 

The  masses  thus  cast  loose  get  frozen  in  during  the  win- 
ter, and  are  imprisoned  by  the  immense  fields  of  sheet  ice, 
five  or  six  feet  thick,  which  form  upon  the  surface  of  the 
water  over  all  the  gulfs  and  bays  in  those  regions.  When 
the  spring  opens,  the  whole  mass  breaks  up  and  is  driven 

I 


194  THE    ICEBERG. 

out  by  the  winds  and  the  currents  down  Baffin's  Bay  into 
the  Atlantic  Ocean  in  a  stream  of  icebergs,  floes,  and  vast 
fields  of  broken  ice,  which  come  on  grinding  and  crashing 
together  with  a  force  and  turmoil  which  it  is  frightful  to 
witness,  even  in  the  daytime,  and  which  it  is  still  more 
frightful  to  hear  at  night,  when  the  noise  which  they  some- 
times make  is  like  a  perpetual  roll  of  thunder. 

It  is  only  by  whalemen  and  adventurers  in  arctic  ex- 
ploring expeditions  that  these  scenes  can  be  actually  wit- 
nessed ;  but  persons  who,  like  Lawrence  and  Miss  Almira, 
have  accustomed  themselves,  by  habits  of  thought  and  re- 
flection, to  bring  these  vast  movements  and  operations  of 
nature  home  to  their  minds,  can  in  some  measure  experi- 
ence the  emotions  of  awe  and  grandeur  which  they  are  fit- 
ted to  inspire. 

The  groups  that  had  assembled  on  the  deck  to  see  the 
iceberg  seemed  to  be  very  differently  affected  by  the  spec- 
tacle. Some  uttered  exclamations  of  surprise  and  delight. 
Others  began  to  make  estimations  in  respect  to  its  size,  and 
its  distance  from  the  ship.  Others  were  silent,  and  seemed 
to  gaze  upon  the  spectacle  with  solemn  awe. 

Mrs.  Gray  found  her  friend  Caroline,  as  she  .called  her, 
and,  taking  her  stand  by  her  side,  she  said, 

"Wonderful!  isn't  it?    It  looks  like  a  great  camel." 

"  Oh  no  !"  said  her  friend ;  "  it  looks  more  like  a  fortifi- 
cation, with  a  great  round  tower  in  the  middle — all  in 
ruins." 

"  Now  I  think  it  looks  more  like  a  camel,"  said  Mrs. 
Gray.  "  That  is  not  like  a  round  tower.  That  is  the  cam- 
el's hump." 

Miss  Almira  had  withdrawn  a  little  way  from  the  rest, 
and  stood  gazing  at  the  iceberg  in  silence.  Lawrence  had 
explained  to  her  the  evening  before  how  these  mountains 
of  ice  were  produced,  and  her  imagination  was  busy  in  pic- 


A   SIGHT   AT   SEA. 


195 


THE   ICEBEKG. 


turing  the  process  by  which  the  immense  mass  was  lormeu 
far  in  the  interior  of  Greenland,  where  the  foundations  of  I* 
had  been  laid  perhaps  a  thousand  years  ago,  in  a  fall  of 
snow,  or  hail,  or  freezing  rain,  high  up  on  the  slope  of  a 
mountain  side.  As  its  thickness  gradually  increased  by 
new  accumulations,  it  began  to  acquire  weight,  and  slowly 
to  work  its  way  down  the  incline.  She  imagined  the  vast 
field  in  this  way  slowly  advancing  on  its  course  year  after 
year,  and  century  after  century,  through  long  arctic  nights 
of  stillness,  solitude,  and  cold,  the  idea  of  which  filled  her 
with  awe.  She  thought  of  the"  duration  and  grandeur  of 
this  slow  but  irresistible  progress  to  the  sea — of  the  sub- 
lime launching  there  of  the  fragment  which  formed  the  ice- 
berg now  in  view — breaking  off,  as  it  must  have  done,  from 


196  THE    ICEBERG. 

its  attachment  to  the  mass  behind  it  with  a  sound  like  the 
crash  of  thunder — and  then  of  its  rolling  over  upon  its  side, 
and  swinging  to  and  fro  with  slow  oscillations  till  it  found 
its  proper  equilibrium — and  of  the  waves  which  it  set  roll- 
ing off  in  all  directions  over  the  bay. 

At  this  moment,  happening  to  turn  her  face  a  little,  she 
saw  that  Lawrence  was  standing  at  her  side.  They  looked 
at  each  other  with  a  smile  of  recognition  and  sympathy, 
but  did  not  speak.  Just  then  the  fog,  through  an  opening 
of  which  the  iceberg  had  been  seen,  began  to  close  over  it, 
and  it  soon  disappeared. 

Lawrence  then  turned  to  Mrs.  Gray  again. 

"  Well,  Mrs.  Gray,"  said  he, "  it  seems  to  be  gone.  Will 
you  remain  upon  deck  any  longer,  or  shall  I  assist  you  to 
go  back  to  the  saloon?" 

Mrs.  Gray  said  it  was  rather  damp,  and  she  thought  it 
would  be  better  for  her  to  go  down.  Almira  said  she 
would  remain  a  little  longer,  and  see  whether  the  iceberg 
would  come  in  sight  again.  So  Lawrence,  taking  Mrs. 
Gray's  glass  in  his  hand,  offered  her  his  arm,  and  conducted 
her  back  to  her  seat  in  the  saloon.  When  she  had  taken 
her  seat,  he  sat  down  opposite  to  her.  She  was  much  grat- 
ified to  see  that  he  did  not  appear  to  be  in  any  haste  to 
leave  her  and  return  to  the  company  of  the  young  ladies 
on  deck,  and  she  began  to  talk  to  him  about  Flippy. 

"  I  am  very  much  obliged  to  you,"  she  said, "  for  taking 
so  much  interest  in  my  boy.  He  seems  to  be  very  fond  of 
you." 

"  He  is  a  very  bright  boy,"  said  Lawrence ;  "  I  like  him 
very  much." 

"  He  is  bright  enough,  I  suppose,"  said  Mrs.  Gray, "  but 
he  is  a  great  bother.  He  is  always  making  me  trouble. 
He  is  very  much  interested  in  the  instructions  which  you 
give  him,  though  I  am  afraid  that  he  does  not  always  get 


WINNING    A    GOOD    OPINION.  197 

things  straight.  There  was  one  thing  he  said  a  day  or 
two  ago  which  surprised  me  very  much.  He  said  you 
told  him  that  you  could  not  make  a  fire  any  hotter  by 
blowing  it  with  the  bellows.  I  told  him  I  was  sure  it  could 
be  made  a  great  deal  hotter." 

"You  were  entirely  right,  Mrs.  Gray,"  said  Lawrence. 
"  It  can  be  made  a  great  deal  hotter." 

"  I  knew  it  could,"  said  Mrs.  Gray,  "  and  with  the  same 
coal  too.  He  said  it  could  not  be  made  hotter  with  the 
same  coal." 

Lawrence  thought  there  might,  perhaps,  be  some  ques- 
tion whether  it  was  Flippy  or  his  mother  that  did  not "  get 
things  straight"  in  this  case.  But  he  was  not  certain,  after 
all,  but  that  Flippy  had  stated  the  case  wrong. 

"There  was  some  mistake  somewhere,"  said  Lawrence. 
"  Perhaps  I  did  not  make  the  case  quite  clear,  or  Flippy 
may  not  have  expressed  himself  as  he  ought  to  have  done. 
We  can't  expect  boys  of  his  age  to  be  always  very  accu- 
rate in  expressing  their  ideas.  At  any  rate,  you  were  cer- 
tainly right  in  thinking  that  a  fire  may  be  made  hotter  by 
blowing  it." 

After  remaining  some  time  longer  and  conversing  with 
Mrs.  Gray  on  a  number  of  indifferent  topics,  Lawrence  took 
leave  of  her  and  went  upon  deck,  saying  that  he  would  go 
and  see  if  the  iceberg  had  come  in  sight  again.  Very  soon 
after  he  went  away,  the  lady  whom  Mrs.  Gray  called  Caro- 
line returned.  As  soon  as  she  had  taken  her  seat,  Mrs. 
Gray  said, 

"  I  find  I  was  entirely  mistaken  about  Mr.  Wollaston. 
He  is  one  of  the  most  perfect  gentlemen  I  ever  knew.  It 
was  all  Flippy's  work,  in  giving  me  a  wrong  idea  of  him. 
He  always  makes  a  mess  of  every  thing  he  meddles  with. 

"  Besides,"  she  added, "  he  did  not  say  any  such  a  thing 
as  that  fire  could  not  be  made  any  hotter  by  blowing  it.  1 
knew  he  did  not." 


198  THE    WORK    OF    THE    ARCTIC  ICE. 


CHAPTER  XX. 

THE    WOEK    OF   THE    AECTIC    ICE. 

THERE  is  something  very  curious,  which  Lawrence  ex- 
plained a  day  or  two  after  this  to  Miss  Almira  and  to  the 
two  boys,  in  respect  to  the  work  which  the  stream  of  ice- 
bergs and  fields  of  ice-noes  and  of  broken  ice  performs  in 
aiding  the  Gulf  Stream  in  its  work  of  conveying  a  portion 
of  the  heat  of  the  tropics  to  the  regions  around  the  poles. 
The  Gulf  Stream,  as  has  already  been  said,  brings  a  cur- 
rent of  water  fifty  miles  wide  and  a  thousand  feet  deep  for 
a  distance  of  a  thousand  miles  from  the  Gulf  of  Mexico 
into  the  Northern  Seas.  Off  the  coasts  of  Labrador  and 
Newfoundland  this  current  meets  a  great  stream  of  ice 
coming  in  the  contrary  direction,  and  it  is  singular  enough 
that  this  very  flow,  though  coming  from  north  to  south, 
operates  most  effectually  in  continuing  the  movement  of 
the  heat  brought  thus  far  by  the  Gulf  Stream  from  the 
Gulf  of  Mexico-  to  Newfoundland. 

There  are  two  or  three  aspects  in  which  the  operation 
may  be  viewed,  which  will  show  the  truth  of  this. 

In  the  first  place,  as  cold  is  merely  the  absence  of  heat — 
that  is  to  say,  the  contrary  of  it,  the  removing  of  cold  from 
any  place  is  equivalent  to  the  introduction  of  heat  into  it. 
Thus  the  bringing  out  of  so  much  ice  from  the  arctic  re- 
gions operates  to  diminish  the  cold  of  those  regions,  which 
is  only  saying,  in  other  words,  to  increase  the  heat. 

But,  in  the  second  place,  by  looking  at  the  subject  a  lit- 
tle more  particularly,  we  can  see,  to  some  extent,  how  this 
is  done.  The  iceberg,  as  it  moves  through  the  water  on 


INTERCHANGE    OF   COLD    AND    HEAT.  199 

its  way  from  north  to  south,  must  continually  displace,  as 
it  advances,  a  portion  of  water  equal  to  the  bulk  of  the 
part  submerged,  and  this  portion,  or  its  equivalent,  must 
move  from  south  to  north  to  fill  the  space  which  would 
otherwise  be  left  empty.  The  movement  of  the  mass  of 
ice  in  one  direction  necessarily  involves  a  corresponding 
movement  of  an  equal  mass  of  water  in  the  other  direction. 

Thus  -the  immense  stream  of  ice^  in  meeting  the  warm 
water  of  the  Gulf  Stream  at  the  Banks  of  Newfoundland, 
acts  virtually  to  continue  its  movement  toward  the  north, 
each  block  of  ice  contributing  its  portion  of  the  effect  by 
causing  an  equal  bulk  of  water  to  exchange  places  with  it, 
as  it  were,  as  it  comes  on.  It  is  true  that  this  interchange 
does  not  necessarily  take  place  in  the  immediate  vicinity 
of  each  particular  block,  but  it  must  really  take  place 
somewhere,  for  the  level  of  the  sea  at  the  north  remains 
unchanged,  proving  that  the  vacancy  which  would  other- 
wise be  made  by  the  going  out  of  the  ice  is  fully  supplied, 
in  some  way,  by  the  water  flowing  in ;  and  the  result  is  the 
same,  in  respect  to  a  diminution  of  the  cold,  whether  the 
water  which  replaces  the  ice  flows  in  by  the  side  of  the 
outflow,  or  on  the  other  side  of  the  pole,  or  even  by  vapors 
through  the  air. 

Now  the  ice,  when  it  commences  its  movement,  might 
probably  have  been  50°  below  zero ;  but  the  water  which, 
by  its  coming  out,  is  forced  in,  could  not  have  been  lower 
than  27°  above,  as  that  is  the  temperature  at  which  salt 
water  freezes. 

If  it  were  fresh  water  that  was  forced  in  to  take  the 
place  of  the  ice,  it  could  not  be  colder  than  32°  above,  as 
that  is  the  freezing  point  for  fresh  water.  But  the  ordi- 
nary salt  water  of  the  ocean  stands  a  greater  degree  of 
cold  than  that,  and  does  not  freeze  till  it  gets  down  to 
27°.  That  is  one  reason  why  lakes,  and  ponds,  and  rivers 


200  THE    WORK    OF   THE    ARCTIC    ICE. 

inland  freeze  much  sooner  than  bays  and  inlets  from  the 
sea. 

Thus  one  way  is  very  clear  in  which  the  flow  of  the  ice 
to  the  south  has  the  effect  of  carrying  heat  to  the  north — 
by  bringing  away  what  is  intensely  cold,  and  causing  its 
place  to  be  supplied  by  something  80°  or  90°  warmer.  But 
this  difference  of  temperature  is  by  no  means  the  whole,  or 
even  the  principal  part  of  the  difference  between  water  and 
ice,  for  the  water  carries  with  it  not  only  the  heat  which 
is  employed  in  raising  .its  temperature,  but  also  that  much 
larger  portion  which  is  required  to  maintain  it  in  its  liquid 
state — namely,  one  hundred  and  forty  units  of  heat  to  each 
pound — which  amount  is  latent,  as  heat,  in  the  water,  be- 
ing in  action  in  it  as  force,  altering  in  some  mysterious 
way  the  internal  constitution  of  the  substance  of  the  water, 
so  as  to  maintain  it  in  a  liquid  state  without  altering  its 
temperature — that  is,  without  making  it  feel  any  warmer 
to  the  touch,  or  indicating  any  higher  degree  of  heat  by 
the  thermometer. 

This  is  a  fundamental  consideration — one  which  it  is 
very  important  that  any  one  studying  the  philosophy  of 
heat  should  clearly  understand  and  fix  in  his  memory — 
namely,  that  you  must  extract  a  very  large  amount  of  heat 
from  water,  after  you  get  it  cold  enough  to  begin  to  freeze, 
in  order  to  effect  the  freezing  of  it.  And,  what  is  very 
remarkable,  and  very  important  to  be  understood  and  re- 
membered, it  is  found,  by  the  most  exact  and  careful  ob- 
servations, that  precisely  this  amount  of  heat,  the  taking 
away  of  which  was  required  to  allow  the  water  to  become 
solid,  must  be  restored  to  it  to  make  it  liquid  again. 

And  when  the  heat  is  thus  restored,  although  it  would 
be  enough,  if  it  were  employed  in  raising  the  temperature 
of  the  water,  to  make  it  scalding  hot,  it  does  not  raise  the 
temperature  at  all.  It  becomes  latent,  as  the  scientific 


THE    HEAT    OF   LIQUEFACTION.  201 

books  express  it,  which  word  means  hidden.  It  is  em- 
ployed in  altering  the  constitution  of  the  body  from  a  solid 
to  a  liquid.  But,  though  thus  latent  as  heat,  it  is  not  lost. 
It  is  not  even  diminished.  It  all  remains  at  its  post,  oper- 
ating in  the  work  of  maintaining  the  water  in  a  liquid  state, 
after  it  has  made  it  liquid,  and  must  be  again  given  out  in 
full  without  the  least  abatement  or  diminution,  or,  rather, 
must  be  again  taken  out  before  the  water  can  become  solid 
again. 

The  heat  which  is  thus  absorbed  by  a  solid  body  in  mak- 
ing it  liquid,  and  thus  becomes  latent — that  is,  impercepti- 
ble to  the  senses  in  any  way — is  called  the  heat  of  fusion 
or  of  liquefaction.  It  is  considered  as  becoming  a/orce, 
which  is  exercised,  as  we  have  already  said,  in  maintaining 
the  body  in  a  liquid  state.  From  this  and  similar  cases 
has  arisen  the  idea  of  considering  heat  as  a  form  of  force ; 
and,  as  we  have  no  distinct  idea  of  force  except  as  mani- 
festing itself  in  some  kind  of  motion,  or  tendency  to  mo- 
tion, it  is  customary  with  some  writers  to  represent  heat 
as  a  mode  of  motion.  -All  that  we  certainly  know  is  that, 
in  some  secret  way,  when  ice  is  thawed  a  great  amount  of 
heat  mysteriously  disappears,  and  in  some  way  acts  as  a 
force  to  keep  the  water  liquid ;  and  that  exactly  this 
amount,  neither  less  or  more,  must  be  abstracted  before 
it  can  become  solid  again. 

This  is  the  reason  why  a  piece  of  ice  in  a  glass  of  water 
will  cool  it  so  much  more  than  a  piece  of  white  marble 
would  of  the  same  size,  even  though  the  marble  were  just 
as  cold.  The  reason  is  that  the  marble  would  only  draw 
oif  enough  heat  from  the  water  to  warm  itself  up  to  the 
temperature  of  the  water ;  whereas  the  ice  would  absorb 
enough  not  only  to  warm  itself  up  to  that  temperature, 
but  also  enough  to  liquefy  itself,  which  would  require 
about  ten  or  fifteen  times  as  much,  the  exact  amount  de- 

12 


202  THE    WOEK    OF   THE    ARCTIC    ICE. 

pending  upon  the  temperature  of  the  water  on  which  the 
experiment  was  made,  and  on  other  circumstances.  In 
other  words,  a  lump  of  ice  will  extract  as  much  heat  from 
a  glass  of  water — that  is,  will  cool  it  as  much — as  ten  or 
fifteen  pieces  of  marble  of  the  same  size  and  just  as  cold! 
In  the  same  manner,  the  vast  icebergs  and  fields  of  ice 
which  come  down  from  the  north  extract  a  vast  amount 
of  heat  from  the  water  in  which  they  melt — not  merely 
enough  to  warm  the  substance  of  them  up  to  the  tempera- 
ture of  the  water,  but  also  to  liquefy  them,  which  requires 
ten  or  fifteen  times  as  much  as  would  be  required  merely 
to  warm  them. 

It  is  on  a  principle  almost  identical  with  this  that  water 
acts  so  efficiently  in  extinguishing  fire,  namely,  through 
the  enormous  quantity  of  heat  which  is  absorbed  by  it  in 
being  converted  into  steam.  A  pound  of  cold  sand  or 
ashes  thrown  upon  a  fire  would  cool  it  only  to  the  extent 
of  the  quantity  of  heat  required  to  raise  the  temperature 
of  the  sand  or  the  ashes  up  to  that  of  the  burning  fuel. 
But  a  pound  of  water  thrown  on  has  not  only  to  be  heated 
— that  is,  to  have  its  temperature  raised,  which  would  of 
itself  require  more  heat  than  the  sand  or  the  ashes,  on  ac- 
count, as  will  hereafter  be  shown,  of  its  greater  capacity 
for  heat,  but  also  has  to  be  vaporized,  which  requires  a 
very  large  quantity  of  heat  besides.  Thus  the  special  effi- 
ciency of  water  in  extinguishing  fires  depends  upon  the 
enormous  quantity  of  heat  of  vaporization  which  it  absorbs 
from  it.  There  are  other  effects  produced  by  the  water 
which  aid  in  the  result,  but  this  is  the  principal  source  of 
the  cooling  and  extinguishing  power  of  the  water  in  its 
action  upon  fire. 

It  is  calculated  that  an  iceberg  will  cool  at  least  twice 
its  bulk  of  water,  from  being  blood-warm  to  the  freezing 
point,  vnthout  warming  itself  at  all,  but  only  melting  it- 


FEELING   FOR   AN    ICEBERG.  203 

self — that  is,  the  heat  which  it  derives  from  the  water 
around  it,  and  which  is  spent  in  liquefying  it,  without  rais- 
ing the  temperature  of  the  substance  of  it  at  all,  is  so  great 
that  the  loss  of  it  will  cool  more  than  twice  its  bulk  of 
water  50°. 

In  consequence  of  this  absorption  of  heat  from  all  the 
water  around  it,  a  melting  iceberg  lies  always  in  the  mid- 
dle of  a  vast  bed  of  cold  water,  extending  for  a  great  dis- 
tance from  it  on  every  side,  by  means  of  which  the  seamen 
can  "  feel"  for  the  approach  of  one,  as  Lawrence  expressed 
it,  by  means  of  the  thermometer  in  foggy  weather. 

One  day,  when  Lawrence  was  walking  upon  the  deck 
with  Miss  Almira,  she  observed  that  the  seamen  were  let- 
ting something  down  into  the  water,  and  then  carefully 
examining  it  when  they  brought  it  up.  Miss  Almira  asked 
Lawrence  what  they  were  doing.  He  said  they  werefeel- 
ing  for  something,  and  asked  her  to  guess  what  it  was. 
She  said  that  she  should  have  thought  it  was  for  a  shoal 
or  for  a  sand-bank,  were  it  not  that  the  line  Was  not  long 
enough  for  a  sounding-line.  Lawrence  said  that  they  were 
feeling  for  an  iceberg,  or,  rather,  feeling  to  ascertain  wheth- 
er there  was  one  before  them  on  their  course  that  they 
were  in  danger  of  encountering. 

"  Every  great  mass  of  ice  in  this  latitude,"  he  said, "  and 
in  a  calm  day,  lies  in  the  centre  of  a  sphere  of  cold,  which  it 
has  formed  around  it,  the  lower  part  of  it  consisting  of 
water,  and  the  upper  part  of  air.  The  chill  which  it  pro- 
duces extends  sometimes  for  a  mile  or  two,  and  the  exist- 
ence of  this  chill  diminishes  very  much  the  danger  of  the 
voyage  by  the  warning  that  it  gives.  When  the  weather 
is  clear,  the  icebergs  can  be  seen  at  a  sufficient  distance ; 
and  even  field-ice  produces  a  peculiar  effect  upon  the  sky 
above  it,  which  gives  seasonable  notice.  But  in  fogs,  and 
in  dark  and  rainy  nights,  the  increasing  coldness  of  the  air, 


204  THE    WORK    OF   THE    ARCTIC    ICE. 

and  more  especially  that  of  the  water,  as  the  vessel  comes 
within  the  brink  of  danger,  are  the  only  warnings. 

"  There  is  another  very  curious  and  very  important  prin- 
ciple in  respect  to  the  manner  in  which  the  ice-field  and 
icebergs  act  in  aiding  the  transfer  of  heat  from  the  polar 
to  the  equatorial  regions,  and  thus  equalizing  in  some  de- 
gree the  temperature  of  the  globe.  From  the  mass  of  cold 
water  which  lies  beneath  and  around  the  ice,  a  current  is 
all  the  time  flowing  downward  toward  the  bottom  of  the 
sea,  and  thence  onward  toward  the  south,  under  the  warm- 
er water  which  has  come  from  the  south  on  the  surface. 
The  effect  is  just  the  reverse  of  that  produced  by  candles 
or  lamps  in  a  room.  From  a  dozen  of  such  lamps  or  can- 
dles burning  in  a  cool  room,  streams  of  heated  air  are  all 
the  time  ascending  and  spreading  in  every  direction  along 
the  ceiling,  over  the  cooler  air  below.  When  there  is 
smoke  or  steam  in  these  currents,  their  course  is  made  dis- 
tinctly visible. 

"On  the  same  principle,  but  in  a  contrary  way,  from 
every  iceberg  floating  in  the  sea,  we  should  see,  if  our  eyes 
could  penetrate  to  the  depths  below  them,  and  if  there  was 
any  change  produced  in  the  color  of  the  water  to  make 
the  currents  visible,  a  slowly  descending  stream,  of  vast 
volume,  flowing  beneath  the  warmer  water  of  the  surface 
above.  These  cold  descending  streams,  which  come,  in 
proper  measure  and  degree,  from  every  field,  and  floe,  and 
fragment  of  ice,  join  below  with  the  vast  current  of  cold 
water  flowing  from  the  north  to  the  south  to  take  the 
place  of  the  warm  current  at  the  surface  from  south  to 
north.  The  existence  of  these  two  currents,  and  the  differ- 
ence of  their  temperature,  is  fully  shown,  by  proper  ob- 
servations, with  sounding-lines  and  other  instruments,  as 
clearly,  though  not  quite  so  easily,  as  the  outgoing  current 
of  warm  air  at  the  top  of  an  open  door  in  a  warm  room, 


HEAT    IN    COLD    WATEK. 


205 


INCOMING   AND   OUTGOING   CURRENTS. 


and  the  incoming  one  of  cold  air  at  the  bottom  of  the  door, 
by  the  flame  of  a  candle." 

At  one  time  when  Lawrence  was  talking  with  the  boys 
on  these  subjects  in  the  saloon,  just  after  tea,  Flippy  made 
some  remark  which  implied  that  it  seemed  strange  to  him 
to  talk  about  heat  in  connection  with  icebergs  and  cold 
water,  which  he  thought  had  no  heat  in  them  at  all. 

"  Yes,"  said  Lawrence, "  you  are  perfectly  right.  There 
is  no  heat  in  them,  as  the  word  heat  is  usually  understood 
in  common  conversation ;  but  in  science  and  philosophy 
the  word  is  used  in  a  different  way.  In  common  conversa- 
tion, a  thing  is  hot  when  it  feels  hot  to  the  hand ;  and  that 
led  to  an  old  saying,  that  there  is  no  heat  in  fire,  which  is 
very  true,  if  you  mean  by  heat  the  hot  feeling,  for  it  is  plain 
that  there  can  be  no  feeling  at  all  in  fire  of  any  kind. 

"  But  in  science  we  mean  by  heat  that  force,  or  quality, 


206  THE    WORK    OF   THE    ARCTIC    ICE. 

or  whatever  it  is,  in  a  substance  which  causes  it  to  feel  hot 
to  the  hand — that  is  to  say,  not  the  feeling,  but  the  cause 
of  the  feeling.  Now  it  is  proved  very  positively  that  there 
may  be  a  great  deal  of  that  force  or  quality  in  any  sub- 
stance, and  yet  not  enough  to  make  it  feel  hot.  Indeed, 
whether  it  feels  hot  or  not  depends  on  very  slight  arid  ac- 
cidental circumstances.  I'll  show  you. 

"  Steward,"  he  added,  speaking  to  one  of  the  waiters 
who  was  just  then  going  by, "  give  me  a  little  ice,  please." 

The  steward  took  from  under  the  seat  a  shallow  dish, 
filled  with  pieces  of  ice,  and  containing  also  a  spoon.  Law- 
rence then  drew  toward  him  upon  the  table  three  tumblers 
and  a  decanter  of  water,  and  filled  two  tumblers  nearly 
full  from  the  decanter.  He  put  a  piece  of  ice  in  one  of 
them,  and  stirred  it  around  to  cool  the  water.  He  left  the 
water  in  the  second  tumbler  as  it  was.  The  third  tumbler 
he  filled  partly  with  cold  and  partly  with  hot  water,  which 
last  he  took  from  a  tea-pot  containing  hot  water  which 
still  remained  on  the  table,  tempering  the  mixture  so  as  to 
make  it  not  too  hot  for  a  person  to  bear  his  hand  in  it. 

Thus  there  were  three  glasses,  one  containing  ice-cold 
water,  one  which  was  quite  hot,  and  a  third,  which  he 
placed  in  the  middle  between  the  other  two,  of  a  medium 
temperature.  Then  he  directed  Flippy  to  put  two  fingers 
of  one  hand  in  the  cold  water,  and  two  of  the  other  hand 
in  the  warm  water,  and  hold  them  there  until  the  fingers 
in  one  case  had  become  quite  warm,  and  in  the  other  quite 
cold. 

"  Now,"  said  he,  "  dip  your  cold  fingers  into  the  middle 
tumbler,  and  tell  me  how  it  feels." 

Flippy  did  so,  and  said  it  felt  very  warm. 

"And  now,"  said  Lawrence,  "dip  the  warm  fingers  in." 

He  did  so,  and  exclaimed, 

"  Ah  !  now  it  feels  quite  cold." 


WATER  BOTH  COLD  AND  HOT  AT  ONCE.       207 

"  So  you  see,"  said  Lawrence,  "  that  the  feeling  in  our 
hands  is  no  criterion  even  of  temperature,  much  less  of  the 
amount  of  heat — the  cause  of  temperature  —  which  may 
exist  in  great  quantities,  and  yet  be  entirely  disguised." 

John  was  very  much  interested  in  trying  this  experi- 
ment too,  and  he  carried  the  glasses  over  to  Miss  Almira, 
who  was  sitting  at  the  time  on  the  other  side  of  the  saloon. 
She  said  she  had  seen  the  experiment  described  in  books, 
but  had  never  tried  it  before,  and  was  very  glad  of  the 
opportunity. 

"So  you  see,"  said  Lawrence,  when  John  and  Flippy 
came  back  with  the  glasses,  "if  there  was  an  animal  whose 
blood  was  naturally  as  warm  as  your  fingers  became  in  the 
warm  water,  the  middle  water  would  always  seem  cold  to 
them ;  and,  on  the  other  hand,  if  there  were  animals  whose 
blood  was  as  cold  as  ice-water,  and  they  were  sensible  to 
the  feeling  of  heat,  no  water  that  remained  unfrozen  would 
feel  cold  to  them  in  the  coldest  winter  weather.  We  know 
that  there  is  some  heat  in  the  coldest  substances  existing 
in  nature,  for,  however  cold  they  are,  the  chemists  can  by 
artificial  means  make  them  colder." 

So  Lawrence  called  the  steward,  and,  pointing  to  the 
glasses  which  they  had  been  experimenting  with,  asked 
him  to  take  them  away. 


208  HEAT    A   POEM    OF    FORCE. 


CHAPTER  XXI. 

HEAT   A   FOEM    OF   FOECE. 

HEAT  used  to  be  considered  as  a  very  subtle  and  vola- 
tile substance  which  was  emitted  from  the  sun  and  per- 
vaded all  other  substances  in  nature,  and,  when  it  was  so 
considered,  it  was  designated  by  the  name  of  caloric.  It 
was  finally  proved  not  to  be  a  distinct  substance,  and  that 
in  a  very  remarkable  way.  It  was  done  by  boring  an  iron 
cannon  under  water,  the  water  being  heated  by  the  fric- 
tion. Now,  if  the  heat  had  been  a  substance  residing  in 
the  iron,  the  supply  would,  after  a  while,  have  become  ex- 
hausted, and  the  boring  would  have  ceased  to  heat  the 
water.  But  it  was  found  that  the  friction  did  not  so  cease 
to  evolve  heat ;  on  the  contrary,  the  heat  continued  to  be 
produced  as  long  as  the  boring  was  continued.  From  this 
and  from  a  great  many  other  similar  experiments  and  ob- 
servations, and  after  half  a  century  of  very  earnest  discus- 
sions, in  which  the  whole  scientific  world  took  an  active 
part,  it  has  come  to  be  universally  believed  that  heat  is  a 
form  of  force,  and  the  old  word  caloric,  with  the  theory 
which  it  implied,  has  been  abandoned. 

If  any  of  the  readers  of  this  book  should  find  that  they 
do  not  understand  this  very  well — that  they  can  not  get 
any  clear  mental  picture  of  heat  as  a  form  of  force,  or  of 
heat  being  changed  into  force,  or  of  force  changed  into 
heat,  they  have  reason  to  feel  encouraged,  for  those  who 
have  made  the  greatest  advances  in  the  study  of  this  sub- 
ject find  continually  open  before  them  glimpses  into  re- 
gions of  thought  where  they  can  see  nothing  clearly.  And 


MYSTEEIES    OF    NATUEE.  209 

when  they  advance  farther,  so  as  to  make  tolerably  clear 
what  had  before  seemed  mysterious  and  incomprehensible, 
in  so  doing  they  always  bring  other  regions  dimly  into 
view  beyond,  perhaps  more  mysterious  and  incomprehensi- 
ble still.  There  is  no  coming  out  to  the  end,  in  the  study 
of  nature,  any  where.  The  field  widens  and  expands  more 
and  more  the  farther  we  advance. 

If,  therefore,  you.  understand  clearly  the  special  points 
which  I  have  endeavored  to  explain  in  this  volume,  and 
begin  to  see  before  you  many  others,  in  the  contemplation 
of  which  your  thoughts  get  bewildered  and  lost,  you  have 
reason  to  think  you  are  all  right — that  is  to  say,  that  you 
are  on  the  right  road.  There  are  no  other  roads  but  such 
as  this  into  the  vast  field  of  science  open  to  the  exploration 
of  man.  Those  who  have  advanced  the  farthest,  and  who 
understand  the  most,  see  before  them  the  greatest  area, 
that  remains  to  be  explored,  and  is  yet  involved  in  inscrut- 
able mystery. 

Lawrence  had  some  conversation  with  Miss  Almira  on 
this  subject  one  morning,  after  the  Banks  had  been  passed, 
and  when  the  ship  was  steaming  on  through  the  clearer 
atmosphere  arid  under  the  purer  sky  beyond.  There  was 
a  pleasant  breeze  blowing  from  the  southeast,  but  as  the 
vessel  was  going  toward  the  northwest  —  that  is,  nearly 
in  the  same  direction  with  the  wind — and  as  the  velocity 
of  the  wind  was  just  about  the  same  as  that  of  the  vessel, 
it  seemed  calm  upon  the  decks,  and  a  great  many  ladies 
were  seated  upon  the  settees  and  upon  their  folding  chairs, 
in  the  wide  open  part  of  the  upper  deck  between  the  wheel- 
houses,  where  the  view  over  the  water  forward  was  nearly 
uninterrupted.  Some  were  reading,  some  were  engaged  in 
work,  and  some  in  conversation,  and  all  were  animated  with 
the  thought  that  they  had  passed  over  the  most  disagree- 
able and  only  dangerous  part  of  the  way,  and  were  enjoy- 


210  HEAT    A    FORM    OF    FOKCE. 

ing  pleasant  anticipations  of  a  safe  arrival  at  Liverpool 
after  a  few  more  days. 

Lawrence  provided  a  seat  for  Miss  Almira  at  a  place 
which  commanded  a  good  view  "  ahead,"  and  had  then 
taken  a  seat  beside  her.  They  had  been  talking  for  some 
time  on  various  subjects  not  at  all  connected  with  the  sci- 
ence of  heat — about  America,  the  'scenery  in  different  parts 
of  the  country  where  they  both  had  traveled,  and  the  dif- 
ferent characteristics,  manners,  and  customs  of  the  large 
cities.  Lawrence  had  a  strong  desire  to  ask  Miss  Almira 
what  her  other  name  wras,  and  where  she  lived,  but  he  was 
not  sure  that  it  would  be  quite  discreet  to  do  so,  knowing 
well  that  it  is  a  rule  of  polite  society  that  persons  meeting 
thus,  as  it  were,  by  chance  in  public  places  ought  not  to  be 
inquisitive  about  each  other.  * 

In  the  course  of  the  conversation,  and  in  alluding  to  their 
approaching  arrival,  Almira  said  that  she  was  glad  that  she 
had  met  Lawrence,  and  that  she  was  much  indebted  to  him 
for  many  new  ideas  which  he  had  given  her  on  scientific 
subjects — ideas,  she  said,  that  had  turned  her  thoughts  in 
new  directions,  and  would  make  her  feel  a  greater  interest 
in  reading  about  such  subjects  than  ever  before.  Among 
other  things,  she  spoke  of  the  thermometer  as  not  measur- 
ing quantity  at  all  in  heat. 

"  No,"  said  Lawrence, "  it  only  marks  points  in  a  line 
of  progress.  We  may  infer  quantities  sometimes  from  two 
or  more  of  its  indications,  but  its  indications  do  not  di- 
rectly denote  quantity  at  all.  Thus,  when  we  say  the  ther- 
mometer is  at  30,  the  30  does  not  denote  30  units  of  heat, 
or  30  quantities  of  heat  of  any  kind.  It  means  simply  that 
the  mercury  is  at  the  thirtieth  mark  on  a  certain  scale.  It 
is  an  ordinal  number  in  reality,  not  a  cardinal  one." 

Almira  said,  in  conversing  farther  on  the  subject,  that 
she  found  it  very  difficult  to  obtain  any  clear  idea  of  latent 


FORCE    STOKED    UP.  211 

•     • 

heat.  "  If  heat  is  motion,"  she  said, "  what  is  latent  mo- 
tion ?  Indeed,  I  can  not  picture  to  mind  a  latent  force  of 
any  kind.  If  two  bodies  are  moving  toward  each  other,  I 
can  form  some  conception  of  the  persistency  of  their  mo- 
tion as  a  force.  But  if  they  are  stopped  by  some  other 
force,  so  that  they  can  not  go  on,  but  only  have  a  tendency 
to  go  on,  what  is  that  tendency  ?  I  can  not  picture  it  to 
my  mind  at  all. 

"  In  the  case  of  coal,  for  example,"  she  said, "  there  is  a 
great  force  stored  up  in  it — a  force  derived  from  the  sun, 
and  which,  when  it  is  released,  acts  with  immense  power. 
But  what  is  a  force  stored  up  f  I  can  only  conceive  of  a 
force  as  acting.  If  it  is  not  acting,  it  does  not  seem  to  be 
force." 

"  It  is  one  of  those  cases,"  said  Lawrence, "  in  which  we 
seem  to  come  to  the  confines  of  human  knowledge — cases 
in  which  we  have  proof  that  certain  things  exist,  and  yet 
the  mode  and  manner  of  their  existence  eludes  our  thought. 
We  can  not  grasp  them,  and,  in  attempting  to  do  so,  we 
become  bewildered  and  lost.  There  are  a  great  many  such 
cases.  Take  the  ideas  of  space  and  of  time,  for  instance. 
We  can  not  picture  to  our  minds  space  or  time  as  coming 
to  an  end,  nor  can  we  picture  them  to  our  minds  as  being 
without  end,  for  we  can  not  conceive  infinity  in  any  form. 
So  in  regard  to  the  ultimate  constitution  of  matter.  The 
common  conception,  perhaps,  of  most  people  is,  that  matter 
consists  ultimately  of  extremely  minute  particles  or  atoms 
which  can  not  be  divided.  But  if  these  particles  have  any 
magnitude  at  all,  it  would  seem  that  they  must  be  com- 
posed of  parts,  and  so  can  not  be  ultimate  /  and  if  they 
have  no  magnitude  at  all,  it  would  seem  that  they  must  be 
nothing. 

"It  is  somewhat  so  in  our  attempts  to  follow  out  the 
idea  of  force  to  its  elementary  nature,"  continued  Law- 


212  HEAT   A    FORM    OF   FORCE. 

rence.  "  It  is  difficult,  if  not  impossible,  for  us  to  form  any 
mental  picture  or  conception  of  the  condition  of  the  force 
that  is  pent  up,  so  to  speak,  in  a  mass  of  coal,  just  as  it  is 
in  respect  to  the  force  held  in  reserve  by  a  bow  in  a  bow- 
gun." 

Just  at  this  point  in  the  conversation,  John  and  Flippy, 
who  had  been  walking  about  and  sometimes  standing  near, 
overheard  these  words,  and  Flippy's  attention  was  caught 
by  them. 

"  Let  us  stop,"  said  he, "  and  hear  what  they  are  saying 
about  a  bow-gun." 

"  When  the  bow  is  drawn,"  continued  Lawrence,  "  the 
force  which  the  boy  employed  in  drawing  it,  if  he  lets  the 
string  fly  immediately,  expends  itself  at  once  in  driving 
the  arrow  through  the  air.  If,  on  the  other  hand,  he  passes 
the  string  over  the  little  peg  made  to  hold  it,  that  force 
would  be  held  in  reserve.  It  is  stored,  as  it  were,  in  some 
mysterious  way,  in  the  elasticity  of  the  bow,  and  may  be 
held  there  for  any  length  of  time  without  increase  or  dimi- 
nution." 

"  No,"  said  John ;  "  for  if  you  keep  it  strained  too  long, 
it  will  take  a  set,  more  or  less,  and  will  not  shoot  the  arrow 
so  far." 

"You  are  right,"  said  Lawrence.  "If  the  bow  is  made 
of  wood,  or  of  any  other  substance  that  is  not  perfectly 
elastic,  some  of  the  force  pent  up  will  expend  itself  in  al- 
tering the  internal  constitution  of  the  wood.  But  if  the 
substance  is  perfectly  elastic,  as,  for  example,  if  the  force  is 
stored  in  compressed  air,  then  it  may  remain  latent,  as  it 
were,  for  a  long  time,  and  when  it  is  released,  precisely  the 
amount  that  was  stored,  neither  more  nor  less,  will  come 
into  action.  We  have  abundant  proof  of  the  fact,  though 
all  our  attempts  to  form  any  satisfactory  mental  picture  or 
conception  of  force  thus  stored  are  vain.  It  is  substan- 


ALMIEA'S  KIDDLE.  ::  4      213 

tially  the  same  with  the  chemical  force  stored  in  coal  by 
the  process  of  vegetation." 

On  the  evening  of  the  day  when  this  conversation  was 
held,  John  was  in  the  saloon  writing  in  his  journal,  when 
Almira  came  and  sat  down  by  him.  He  showed  her  the 
pictures  which  he  had  put  in,  and  read  to  her  what  he  had 
written  about  some  of  them.  Finally  he  told  her  that  he 
wished  that  she  would  write  something  in  his  journal,  that 
he  might  have  it  to  remember  her  by. 

She  said  she  would  do  it  with  pleasure. 

"  I  will  write  a  riddle,"  said  she, "  which  will  remind  you 
of  what  Mr.  Wollaston  told  us  about  force  in  reserve,  so 
that  when  you  see  the  riddle  in  your  book  you  will  not 
only  be  reminded  of  me,  but  also  of  Mr.  Wollaston,  and  of 
what  we  have  learned  from  him  about  heat  and  force  on 
this  voyage." 

So  she  took  the  book,  and  the  next  day  brought  it  back 
to  John.  On  opening  to  the  place,  he  found  this  riddle  : 

RIDDLE. 

He  has  no  wings, 

And  never  sings, 
And  never  speaks  a  word ; 

But  he  can  fly 

Up  very  high — 
As  high  as  any  bird. 

Underneath  this  riddle  was  a  square  piece  of  paper 
gummed  on  by  the  upper  edge,  leaving  the  under  edge 
free.  On  the  paper  was  written  the  word 

ANSWER. 

On  lifting  up  the  paper,  John  saw  a  picture  of  an  arrow 
in  the  act  of  mounting  into  the  air,  as  if  just  shot  off  under 
the  impulse  of  the  force  which  had  been  stored  in  the  elas- 
ticity of  the  bow  by  drawing  the  string. 


214         *     THE    MECHANICAL   EQUIVALENT    OF    HEAT. 


CHAPTER  XXII. 

THE    MECHANICAL    EQUIVALENT    OF    HEAT. 

THAT  heat  is  a  form  offeree,  or  that  heat  and  force  have 
something  in  their  nature  that  is  common,  is  shown  to  the 
satisfaction  of  scientific  men  from  the  fact  that  force  may 
be  derived  from  heat,  and  that  just  to  the  extent  that  force 
is  derived  from  it  the  heat  disappears. 

In  the  same  manner,  also,  heat  may  be  produced  by  the 
expenditure  of  force,  and  just  in  proportion  to  the  force 
expended  is  the  heat  that  is  produced. 

The  unit  of  heat  used  for  measuring,  or,  rather,  for  af- 
fording means  of  expressing  quantities  of  heat,  is,  as  has 
already  been  stated,  the  quantity  which  will  raise  the  tem- 
perature of  one  pound  of  water  one  degree  of  the  English 
thermometer. 

The  unit  of  force  which  is  used  as  a  means  of  denoting 
or  expressing  quantities  of  force  is  the  amount  expended 
in  raising  a  weight  of  one  pound  one  foot  in  height  at  the 
surface  of  the  earth.  It  is  called  a  foot-pound. 

Now,  when  heat  and  force  were  found  to  be  mutually 
convertible  into  each  other,  it  became  at  once  a  very  cu- 
rious question  what  was  the  numerical  ratio  between  them ; 
in  other  words,  how  much  force  any  given  quantity  of  heat 
is  capable  of  producing,  and  the  converse. 

A  great  number  of  investigations  and  experiments,  by 
many  different  philosophers,  have  been  made  for  the  pur- 
pose of  determining  this  point.  It  has  at  length  been 
ascertained  to  the  full  satisfaction  of  the  whole  scientific 
world,  and  it  is  called  the  mechanical  equivalent  of  heat. 


JOULE'S  EXPERIMENT.  215 

I  suppose  that  those  of  my  readers  who  have  never  paid 
special  attention  to  such  subjects  as  these  would  be  quite 
at  a  loss  to  imagine  by  what  kind  of  contrivance  any  cer- 
tain precise  amount  of  force  could  be  converted  into  heat, 
and  the  quantity  of  heat  so  produced  be  exactly  measured, 
so  as  to  establish  the  ratio  of  one  to  the  other.  The  per- 
son who  took  the  most  active  part  in  this  investigation 
was  a  certain  English  engineer  named  Joule.  The  equiv- 
alent which  he  ascertained  by  his  experiments  has  since 
been  abundantly  confirmed  by  numerous  other  experi- 
ments made  in  a  great  variety  of  ways,  and  is  now  univer- 
sally received  as  the  English  expression  of  the  equivalence 
of  force  and  heat,  and  is  known  as  Joule's  Experiment.  It 
is  this ;  and  every  person  interested  in  such  studies  as  these 
ought  to  fix  it  firmly  in  his  memory : 

A  unit  of  heat  is  equivalent  to  seven  hundred  and  seventy  - 
two  foot-pounds. 

That  is  to  say,  the  heat  required  to  raise  1  pound  of  water 
through  1  degree  of  temperature  of  Fahrenheit's  thermom- 
eter may  be  made  to  act  as  a  force  to  the  extent  of  raising 
77 2  pounds  weight  1  foot  high,  or  1  pound  772  feet  high, 
or  386  pounds  2  feet  high,  or  to  do  any  other  equivalent 
amount  of  lifting. 

On  the  other  hand,  a  weight  of  772  pounds  falling  1  foot, 
or  1  pound  falling  772  feet,  or  any  other  equivalent  amount 
of  force  exercised  by  a  body  in  falling,  when  arrested,  de- 
velops sufficient  heat  to  raise  1  pound  of  water  1  degree 
of  Fahrenheit's  thermometer. 

The  general  principle  on  which  Joule's  method  of  ascer- 
taining this  equivalent  is  founded  will  be  easily  understood 
by  the  following  engraving.  On  the  right  you  see  an  iron 
weight,  which  descends  along  a  scale  marked  in  feet  and 
inches.  The  cord  from  this  weight  passes  over  a  pulley 
above,  and  thence  is  carried  to  the  left,  where  it  is  wound 


216  THE    MECHANICAL    EQUIVALENT    OF    HEAT. 


JOULE'S  APPARATUS. 

many  times  around  a  vertical  axle.  The  upper  part  of  this 
axle  has  a  winch,  by  means  of  which  the  axle  may  be  wound 
up,  and  the  weight  set  at  any  point  on  the  scale. 

The  lower  part  of  the  axle  passes  down  into  a  vessel  of 
water,  and  has  vanes  attached  to  it,  which,  by  the  revolu- 
tion of  the  axle,  are  made  to  agitate  the  water  and  produce 
friction  among  the  particles.  You  would  not  suppose  that 
the  friction,  or  any  other  effect  produced  among  the  parti- 
cles of  water,  would  evolve  heat,  but  it  does  so,  and  that 
in  exact  proportion  to  the  amount  of  force  expended  in 
producing  the  friction.  A  thermometer,  which  you  see 
projecting  its  tube  above  the  vessel  of  water  on  the  left, 
shows,  when  the  experiment  is  made  with  this  apparatus, 
just  how  much  the  temperature  of  the  water  has  been 
raised  by  the  descent  of  the  weight  through  any  given 
space.  And  from  these  elements — the  weight  of  the  de- 
scending iron  and  that  of  the  water  also  being  known — it 
is  easy  to  calculate  how  many  units  of  heat  have  been 
transferred  to  the  water  by  the  descending  force  of  the  iron. 


FRICTION    AND    HEAT.  217 

The  engraving  only  shows  the  general  principle  of  the 
method.  In  the  actual  experiments  made  by  Joule,  a  great 
many  contrivances  were  necessary  to  guard  against  or  al- 
low for  sources  of  error  which  would  otherwise  have  af- 
fected the  result,  such  as  the  escape  of  heat  through  the 
walls  of  the  vessel,  and  the  waste  of  force  in  the  friction 
of  the  pulley.  These  details  we  have  not  space  to  explain, 
nor  is  it  necessary  to  attempt  it,  as  it  is  only  the  general 
principle  which  we  wish  here  to  show. 

The  great  thing  is  to  remember  the  result,  which  is  a 
principle  of  fundamental  importance  in  the  science  of  heat 
and  force,  namely : 

That  the  force  equal  to  that  exercised  by  1  pound  de- 
scending 772  feet  is  equivalent  to  a  quantity  of  heat  suffi- 
cient to  raise  the  temperature  of  1  pound  of  water  1  En- 
glish degree.  In  other  words,  that 

1  unit  of  heat  is  equivalent  to  772  foot-pounds  of  force. 

There  are  a  great  many  ways  by  which  the  conversion 
offeree  into  heat,  and  the  evolution  of  heat  by  the  expend- 
iture of  force,  is  exemplified  in  natural  phenomena  occur- 
ring around  us,  or  may  be  made  manifest  by  artificial  con- 
trivances. One  of  the  most  curious  and  striking  of  these 
last  is  shown  in  the  engraving  on  the  following  page. 

The  tube  on  the  left,  which  is  held  between  the  arms  of 
a  wooden  grip,  as  shown,  is  an  iron  one,  and  is  half  filled, 
at  the  commencement  of  the  experiment,  with  water.  On 
turning  the  wheel  the  tube  is  made  to  revolve,  and  the 
heat  produced  by  the  friction  soon  becomes  so  great  as  to 
boil  the  water,  and  thus  soon  to  force  out  the  cork  with 
an  explosion,  by  the  expansive  force  of  the  steam. 

Here  the  muscular  force  of  the  person  turning  the  wheel 
is  conveyed  by  the  mechanism  to  the  tube,  and  there,  be- 
tween the  tube  and  the  two  arms  of  wood  clasping  it,  it  is 
expended  in  friction,  and  so  transformed  into  heat.  The 

K 


218 


THE    MECHANICAL    EQUIVALENT    OF    HEAT. 


HEAT  DEBIVED  FBOM  FOKOE  OF  FBICTION. 

heat  is  converted  into  force,  which  it  expends  in  altering 
the  internal  constitution  of  the  water  by  converting  it  into 
steam,  and  this  force  expends  itself,  or  a  portion  of  itself, 
in  projecting  the  cork  into  the  air,  as  you  see. 

This  is  an  example  of  the  conversion  of  force  into  heat, 
namely,  force  expended  in  friction.  Instances  innumerable 
are  occurring  all  around  us  of  heat  acting  as  a  force — that 
is,  being  converted  into  force.  Heat  acts  as  a  force  in  ex- 
panding a  vast  variety  of  substances.  It  expands  air,  and 
all  gaseous  substances.  It  expands  iron,  and  all  metals. 
The  expansion  of  a  metal  like  iron  is  shown  by  heating  a 
bar  or  rod,  and  it  is  found  by  accurate  measurement  that 
its  length  increases.  An  experiment  often  made  at  public 
lectures  to  make  the  expansion  of  iron  by  heat  perceptible 
to  the  eye  is  shown  in  the  following  engraving. 

A  long  lamp,  with  a  line  of  wicks,  is  made  to  burn  under 
an  iron  bar,  A,  which  is  held  firmly  by  a  binding  screw  at 
one  end,  B,  and  passes  through  an  opening  in  the  upright 
standard  at  the  other  end,  through  which  it  is  free  to 
move.  As  it  expands  by  the  heat,  the  outer  end  presses 


EXPANSION    OF    IRON. 


219 


HEAT   CONVERTED  INTO   EXPANSIVE  FORCE. 

against  the  short  or  lower  end  of  the  index,  which,  acting 
as  a  lever,  moves  the  upper  end  a  very  considerable  dis- 
tance over  the  graded  arc  K,  which  makes  the  progress 
of  expansion,  as  the  iron  becomes  more  and  more  heated, 
very  perceptible. 

The  expansion  of  iron,  though  it  seems  very  slight  when 
measured  by  the  amount  of  increase  in  the  length  of  the 
bar,  is  really  the  expression  of  a  prodigious  force,  as  is 
shown  when  the  iron  bar  is  immovably  confined  at  one  end, 
and  is  large  and  thick  enough  not  to  be  bent  to  one  side 
by  the  expansion,  in  which  case  it  is  found  that  it  requires 
an  enormous  force  to  resist  the  advance  of  the  free  end  of 
the  bar. 

There  is  another  way  of  showing  the  vast  force  brought 
into  action  by  this  expansion,  and  that  is  by  the  force  with 
which  the  iron  contracts  again  when  it  is  allowed  to  cool. 
Heavy  walls  of  masonry,  that  had  leaned  over  out  of  the 
perpendicular,  have  been  brought  back  into  place  again  by 
means  of  iron  rods  passing  through  them,  and  screwed  by 
nuts  on  the  outside.  By  heating  these  rods  they  would 
become  lengthened,  and  would  protrude  farther  through 
the  opening.  The  nuts  would  then  be  screwed  up  so  as  to 
prevent  the  outer  ends  of  the  rods  from  being  drawn  back 
again  through  the  wall.  Then  the  rods  would  be  allowed 


220 


THE    MECHANICAL    EQUIVALENT    OF    HEAT. 


to  cool,  and  the  force  which  they  would  exert  in  springing 
back  to  their  former  length  was  found  sufficient  to  draw  in 
the  whole  wall,  massive  and  heavy  as  it  was.  This  method 
was  employed  successfully  some  years  since  in  bringing 
back  into  place  the  walls  of  a  large  public  building  in 
Paris. 


WALLS  BROUGHT  UP. 

Now  the  force  with  which  the   rods,  in  such  a  case, 

shrink  in  cooling,  is  exactly 
that  which  the  force  devel- 
oped by  the  heat  has  to  over- 
come in  expanding  them. 

The  effect  of  heat  in  ex- 
panding iron  is  sometimes 
shown  in  another  way  by 
means  of  an  iron  ball,  hung 
from  a  support  by  a  chain, 
and  a  ring  placed  horizontal- 
ly beneath  it,  the  two  being 
BALL.  *o  adjusted  to  each  other  that 


EXPANSION    OF   VARIOUS   SUBSTANCES.  221 

the  ball  will  slip  easily  through  the  ring  when  it  is  cold. 
By  taking  the  ball  off  from  the  ring,  and  letting  it  hang 
over  the  flame  of  a  spirit  lamp,  it  may  be  heated,  when,  on 
placing  it  upon  the  ring,  it  will  be  found  that  the  ball  has 
become  too  large  to  pass  through. 

Blacksmiths  cause  the  iron  band  which  encircles  a  car- 
riage-wheel— called  the  tire — to  grip  the  wheel  and  to  hold 
the  parts  together  with  prodigious  force,  by  heating  it  first 
in  a  circular  fire,  and  then  putting  it  on  while  it  is  still  hot. 
In  cooling  and  shrinking  again,  the  enormous  force  which 
the  heat  overcame  in  expanding  the  iron  comes  into  action, 
and  it  exerts  sometimes  so  much  power  as  actually  to 
bend  the  spokes  of  the  wheel. 

Heat  expands  in  this  manner  almost  all  substances,  gases, 
vapors,  metals,  rocks,  water,  and  liquids  of  every  kind.  The 
power  of  the  steam-engine  is  all  derived  from  the  expan- 
sive force  produced  by  the  heat  entering  the  steam  after  it 
is  formed  in  the  boiler,  and  there  acting  as  a  force  of  ex- 
pansion. 

In  some  cases  the  expansive  effect  produced  by  heat  is 
not  apparent,  but  it  is  not  the  less  real  on  that  account,  as, 
for  example,  in  the  case  of  wood.  The  woody  fibre  itself, 
and  the  air  filling  the  pores,  are  expanded ;  but,  the  sub- 
stance being  porous,  the  increase  of  bulk  is  taken  up,  so  to 
speak,  in  the  pores,  so  that  the  external  dimensions  of  the 
mass  are  not  sensibly  changed. 

This  tendency  of  iron  to  expand  and  contract  with  the 
changes  in  its  condition  in  respect  to  heat  and  cold  has  to 
be  taken  into  account  in  a  great  many  operations.  For 
example,  if  you  look  at  the  iron  rails  on  a  railroad  in  the 
winter,  or  in  any  cool  weather,  you  will  see  that  the  ends 
do  not  quite  touch  each  other.  There  is  a  little  space  left 
between  each  pair  to  allow  for  the  expansion.  If  the  rails 
were  laid  so  that  they  would  touch  in  the  winter,  they 


222  THE    MECHANICAL    EQUIVALENT    OF    HEAT. 

would  expand  so  much  in  the  hot  days  of  summer  that 
they  would  bulge  each  other  out  of  line ;  and  so  great  is 
the  force  by  which  this  expansion  would  be  effected,  that 
there  would  be  no  practicable  way  of  fixing  the  rails  in 
their  places  so  as  to  prevent  their  being  thus  deranged. 

The  most  solid  rocks  shrink  and  swell  in  this  manner  as 
they  are  alternately  heated  and  cooled.  Several  years 
since  some  scientific  men  connected  with  Harvard  College 
wished  to  perform  some  experiments  which  required  the 
use  of  an  extremely  long  pendulum,  and  they  concluded 
to  make  use  of  the  Bunker  Hill  Monument  for  the  suspen- 
sion of  it.  The  first  thing  was  to  hang  the  pendulum,  and 
then  to  bring  it  to  a  state  of  perfect  rest,  with  a  point  from 
the  lower  part  of  it  directly  over  a  certain  point  marked  on 
the  floor.  But  they  found  that  they  could  not  bring  this 
point  to  a  state  of  permanent  rest  over  the  same  point  on 
the  floor,  and,  after  quite  a  long  series  of  observations  and 
examinations,  they  found  that  the  whole  monument  was 
bent  this  way  and  that  alternately,  every  day,  by  the 
swelling  of  the  sides  of  the  structure  as  the  sun  shone 
upon  them  in  succession,  thus  continually  shifting  the  point 
of  suspension.  In  the  morning,  when  the  sun  shone  on  the 
eastern  side,  the  monument  was  bent  over  toward  the  west 
— but  very  little,  it  is  true,  but  still  to  a  sensible  degree. 
In  the  middle  of  the  day,  when  the  sun  shone  on  the  south 
side,  the  monument  was  bent  toward  the  north,  and  in  the 
afternoon  toward  the  east.  The  effect  was  found,  as  might 
have  been  expected,  to  be  most  marked  and  striking  on 
hot  days,  when  the  sun  shone  bright  and  clear. 

The  rocks  which  form  the  strata  lying  near  the  surface 
of  the  earth,  where  they  are  near  enough  to  come  under 
the  direct  influence  of  the  sun,  must  expand  and  contract 
thus  every  twenty-four  hours,  as  they  are  warmed  by  the 
sun  during  the  day,  and  allowed  to  cool  again  at  night ; 


FISSURES    IN   THE    ROCKS.  223 

and  the  same  effect  must  be  produced  on  a  still  larger  scale 
from  the  changes  of  temperature  produced  by  the  different 
seasons  of  the  year.  The  innumerable  rents,  and  fissures, 
and  crevices  which  we  see  every  where  in  ledges  of  rocks 
lying  near  the  surface  of  the  ground  are  due,  doubtless,  in 
a  large  measure,  to  the  alternate  expansions  and  contrac- 
tions arising  from  this  cause. 

It  is  found  that  not  only  do  almost  all  substances  thus 
expand  by  heat,  but  they  expand  very  regularly — that  is, 
that  within  certain  very  wide  limits  equal  additions  of  heat 
at  all  temperatures  produce  equal  degrees  of  expansion. 

But  I  shall  have  something  more  to  say  in  relation  to 
this  subject  in  the  next  chapter 


224  THERMOMETERS. 


CHAPTER  XXIII. 

THERMOMETERS. 

IT  is  in  consequence  of  the  law  referred  to  at  the  close 
of  the  last  chapter — namely,  that  equal  additions  of  heat 
under  ordinary  circumstances  produce  in  most  substances 
equal  degrees  of  expansion — that  the  state  of  expansion 
or  contraction  of  any  substance  may  be  made  use  of  as  a 
measurement  of  temperature.  An  iron  bar  like  the  one 
shown  in  the  engraving  as  heated  by  flame  would  make  in 
principle  a  good  thermometer,  for  the  needle  would  show 
by  its  position  the  temperature  of  the  surrounding  air,  the 
point  of  it  moving  a  great  way  with  a  very  slight  change 
in  the  length  of  the  bar.  But  it  would  make  a  very  incon- 
venient one  in  practice. 

It  is  found  much  better  to  use  some  liquid  substance,  for 
a  considerable  quantity  of  such  a  substance  can  be  inclosed 
in  a  bulb,  with  a  tube  of  fine  bore  attached  to  it,  and  thus 
a  small  expansion  of  the  whole  mass  in  the  bulb,  by  forcing 
a  slender  thread  of  its  substance  up  the  tube,  will  produce 
a  great  visible  effect.  Water  will  not  answer  very  well ; 
for,  besides  some  other  objections  to  it,  it  would  freeze 
when  the  weather  was  even  moderately  cold. 

Mercury  answers  the  purpose  admirably  well,  but  even 
mercury  freezes  at  39°  below  zero,  and  it  is  often  desirable 
to  measure  temperatures  lower  than  that.  The  tempera- 
ture in  the  Arctic  regions  falls  sometimes  to  60°  below 
zero,  and  even  lower,  and  in  such  a  case  a  mercurial  ther- 
mometer would  be  of  no  use. 

Alcohol  is  much  better  than  mercury  in  this  respect, 


THE    SELF-REGISTERING   THERMOMETER. 


225 


namely,  that  it  will  measure  very  much  lower  tempera- 
tures than  mercury  without  freezing.  When  alcohol  is 
employed,  it  is  usually  colored  red,  so  as  to  make  it  more 
plainly  visible  in  the  tube. 

There  is  a  kind  of  thermometer  called  the  self-register- 
ing thermometer.  It  consists  really  of  two  thermometers, 
one  for  the  greatest  heat  and  one  for  the  greatest  cold, 
both  placed  in  the  same  frame. 


30  £.0  10  0   ,        fO  20 

9  20  10  0  10  20 


SELF-REGISTERING   THERMOMETER. 


The  engraving  gives  a  representation  of  one  of  these 
compound  instruments.  The  upper  part  of  the  instrument 
contains  a  tube  joined  to  a  bulb  filled  with  mercury  (A), 
and  also  a  little  button  of  glass  or  porcelain,  which  you  see 
in  the  tube  just  over  the  figure  20.  When  the  air  grows 
warmer,  it  causes  the  mercury  to  expand,  and  as  it  swells 
in  the  bulb,  and  as  the  column  of  it  advances  in  the  tube, 
it  pushes  this  little  button  before  it ;  and  then,  when  it 
contracts  again,  as  the  weather  grows  cooler,  it  leaves  it 
at  the  farthest  point  which  it  has  reached ;  so  that,  when 
you  come  afterward  to  look  at  your  thermometer,  you  can 
not  only  see  what  the  temperature  is  at  the  time  of  your 
visit,  but  can  also  see  how  hot  it  has  been  during  the  day. 

Below  is  an  alcohol  thermometer  (B),  with  a  somewhat 
similar  button,  only  this  lies  in  the  alcohol  instead  of  be- 
ing before  it,  as  the  one  in  the  upper  tube  was  in  relation 
to  the  mercury.  When  the  weather  grows  cold,  and  the 
alcohol  shrinks  and  draws  back  toward  the  bulb,  it  pulls 

K2 


226  THERMOMETERS. 

the  button  back  with  it  as  far  as  it  goes,  and  leaves  it  there 
when  it  grows  warmer  and  the  alcohol  moves  forward 
again.  Accordingly,  when  you  come  to  look  at  this  part 
of  the  thermometer  in  the  morning,  after  a  cold  night,  you 
can  not  only  see  how  cold  it  is  when  you  look,  but  can  also 
see  by  the  place  of  the  button  how  cold  it  was  at  the  cold- 
est time  during  the  night. 

All  that  is  necessary  to  set  the  instrument  for  a  new  ob- 
servation is  to  turn  it  up  endwise  for  a  moment,  with  the 
end  marked  B  uppermost,  when  the  two  buttons  slide  down 
at  once  to  their  places,  ready  to  begin  to  move  again  at  the 
commencement  of  any  new  change  of  temperature.  It  is 
a  very  curious  instrument,  and  any  boy  who  has  access  to 
one  will  watch  its  indications  with  great  interest,  especial- 
ly in  mornings  in  winter  after  very  cold  nights. 

There  is  something  important  to  be  learned  about  the 
zero,  so  called,  of  the  thermometer,  which  is  the  point  at 
which  the  reckoning  of  the  scale  begins.  In.  the  English 
thermometer  the  zero  point  was  fixed  by  what  was  then 
supposed  to  be  the  greatest  possible  cold,  which  was  that 
produced  by  certain  chemical  mixtures,  and  also  that  of  the 
coldest  climates  then  known,  such  as  Lapland.  But  when 
it  was  found  that  that  was  not  the  greatest  cold,  some 
French  philosopher  thought  it  would  be  better  to  begin 
the  scale  at  the  freezing  point  of  water,  and  to  divide  the 
scale  from  that  to  the  boiling  point  into  100  degrees,  and 
they  called  the  thermometer  so  made  the  Centigrade. 

The  Centigrade  plan  is  now  admitted  to  be  much  better 
than  that  of  Fahrenheit,  but  the  latter  is  so  universally  in 
use  in  English-speaking  countries  that  it  would  be  very 
difficult  to  change  it. 

Several  other  plans  besides  these  two  have  been  pro- 
posed, and  have  been  partially  adopted.  Some  very  nice 
and  elaborate  experiments  and  calculations  have  moreover 


THE  DIFFERENTIAL  THERMOMETER. 


227 


been  made  to  determine  what  is  called  the  absolute  zero ; 
that  is,  the  point  of  absolute  destitution  of  heat,  which  is 
the  point  where  the  scale  should  philosophically  begin. 
It  is  now  supposed  to  have  been  satisfactorily  ascertained 
that  this  point  corresponds  with  about  461°  below  the  zero 
of  Fahrenheit. 

The  greatest  natural  cold  of  the  Arctic  regions  is  from 
60°  to  80°  below  Fahrenheit's  zero. 

There  is  a  very  curious  little  instrument,  which  shows, 
not  the  absolute  temperature  of  any  one  portion  of  the  at- 
mosphere or  of  any  other  substance,  but  the  difference  be- 
tween two  such  portions  near  to  each  other.  It  is  called, 
on  this  account,  the  differential  thermometer.  The  form 
of  this  instrument  is  shown  in  the  engraving  below. 

It  consists  of  a  glass  tube  bent  in  the  form  of  the  letter 
U,  except  that  the  corners  are  more 
nearly  square.  There  is  a  graduated 
scale  adapted  to  each  of  the  two  arms. 
The  lower  part  of  the  tube  is  filled  with 
colored  alcohol,  which,  if  the  instrument 
is  properly  adjusted — that  is,  if  it  con- 
tains an  equal  quantity  of  air  in  each 
of  the  bulbs — will,  in  an  equable  atmos- 
phere, stand  out  at  the  same  height  on 
each  side, 

But  if  now  a  warm  hand  is  brought 
up  and  made  to  clasp  one  of  the  bulbs, 
the  air  within  that  bulb  is  warmed  and 
expanded,  and  the  alcohol  in  that  bulb  is  consequently 
pressed  down  and  forced  to  rise  in  the  other  bulb,  as 
shown  by  the  letters  b  and  a.  Thus  the  difference  in  the 
elevation  of  the  alcohol  in  the  two  arms  shows  the  differ- 
ence in  the  temperature  of  the  air  in  the  two  bulbs.  This 
instrument  is  very  sensitive,  so  much  so  that  a  warm  hand 


DIFFERENTIAL,    THER- 
MOMETER. 


228  THERMOMETERS. 

held  in  the  air  with  the  palm  presented  toward  one  bulb, 
but  on  the  side  opposite  to  the  other,  will  cause  a  decided 
difference  in  the  level  of  the  alcohol  in  the  two  arms. 

There  is  another  instrument  far  more  delicate  than  this 
for  indicating  slight  changes  of  temperature,  which  I  shall 
have  occasion  to  refer  to  in  the  next  chapter. 

Lawrence  described  all  these  different  contrivances  to 
John  and  Flippy  one  day,  and  at  the  close  of  the  conversa- 
tion he  told  them  that  there  was  one  kind  of  thermometer 
which  a  boy  could  make  for  himself,  although  he  admitted 
that  it  would  not  be  good  for  much  when  it  was  made. 
The  boys  were  both  very  curious  to  know  about  this. 

"  It  is  called  an  air  thermometer,"  said  Lawrence, "  be- 
cause the  effect  is  produced  by  the  expansion  of  air. 

"  All  you  want,"  he  added, "  to  make  it  is  a  phial — the 
shorter  and  larger  round  it  is  the  better — a  cork,  and  a 
slender  glass  tube  about  as  large  as  a  pipe-stem,  which  you 
can  get  at  almost  any  glass  store  for  a  few  cents.  You 
bore  a  hole  in  your  cork,  or,  what  is  better,  burn  it  with  a 
hot  wire,  and  put  in  the  glass  tube.  You  fill  the  phial 
about  one  third  full  <ff  water ;  then  you  put  the  cork  into 
the  mouth  of  it,  and  push  the  tube  down  through  the  cork 
until  it  almost,  but  not  quite,  touches  the  bottom ;  then 
you  cement  over  the  top  of  the  cork  with  sealing-wax,  or 
shoemaker's  wax,  or  something  of  the  kind,  and  your  ther- 
mometer is  done — except  that  you  had  better  contrive 
some  way  to  pour  a  little  water  into  your  tube  from 
above,  in  order  to  bring  the  level  of  it  up  above  the  cork, 
where  you  can  see  it,  before  you  set  your  instrument  at 
work. 

"  The  way  it  works  is  this,"  continued  Lawrence:  "When 
the  weather  is  warm,  the  warmth  will  expand  the  air  in 
the  upper  part  of  the  phial,  and  make  it  press  harder  on  the 
surface  of  the  water,  and  so  force  more  of  it  up  into  the 


THE    WATER    THERMOMETER.  229 

tube.  On  the  other  hand,  when  the  weather  becomes  cool- 
er, the  water  in  the  tube  will  fall." 

"  But  how  could  we  tell  how  many  degrees  ?"  asked 
Flippy. 

"  Oh,  if  you  want  degrees  to  your  thermometer,"  said 
Lawrence,  "  you  must  have  a  card,  and  mark  degrees  upon 
it,  and  fasten  it  up  in  some  way  upon  the  cork,  behind  the 
tube." 

"  But  how  can  we  tell  how  to  mark  the  degrees  so  as  to 
have  them  correspond  to  the  degrees  of  a  real  thermome- 
ter?" asked  John. 

"  Ah  !  that  would  be  very  difficult,"  said  Lawrence.  "  I 
don't  think  you  could  do  that  very  well.  Besides,  there 
are  other  very  serious  objections  to  such  a  thermometer. 
In  very  cold  weather  the  water  would  freeze ;  then,  as  the 
top  of  the  tube  would  be  open,  the  water  would  be  all  the 
time  slowly  evaporating  from  it.  Some  vapor,  too,  would 
probably  escape  through  the  cork,  no  matter  how  tight 
you  tried  to  make  it.  I  told  you  the  thermometer  would 
not  be  of  much  use.  You  would  only  have  the  fun  of 
making  it,  and  seeing  the  water  rise  and  fall  in  the  tube  as 
the  weather  changed,  or  as  you  held  it  nearer  to  or  farther 
from  the  fire." 

"  I  mean  to  make  one  as  soon  as  I  get  home,"  said  Flip- 
py, "just  for  the  fun  of  it;  I  don't  care  much  about  the 


230  FORCE    CONVERTED    INTO    HEAT. 


CHAPTER  XXIV. 

FORCE    CONVERTED   INTO    HEAT. 

THERE  were  some  things  in  relation  to  heat  that  Law- 
rence did  not  attempt  to  explain  to  Flippy,  nor  even  to 
John,  inasmuch  as  the  right  apprehension  of  them  involved 
a  niceness  of  thought  and  discrimination,  and  a  power  of 
abstraction  and  generalization  to  which  their  minds  had 
not  yet  become  sufficiently  formed.  He  had  many  conver- 
sations with  Miss  Almira  when  neither  of  the  boys  were 
present,  as  he  did  also  with  many  other  young  ladies,  and 
other  persons  of  both  sexes  and  all  ages  on  board.  Nor 
must  it  be  supposed  that  when  he  was  in  the  company  of 
Almira  he  talked  exclusively,  or  even  generally,  on  scien- 
tific topics.  He  talked  with  her  and  with  all  his  other  ac- 
quaintances on  a  great  variety  of  subjects,  and  very  sel- 
dom, in  fact,  on  those  of  scientific  character.  But  it  is  only 
the  conversations  which  related  to  these  subjects,  and  es- 
pecially to  the  subject  of  heat,  that  are  recorded  in  this 
volume. 

One  of  the  points  which  he  particularly  explained  to  Al- 
mira and  John,  and  which  he  did  not  attempt  to  explain  to 
Flippy,  was  that,  whenever  heat  in  any  way  acted  as  a 
force,  it  disappeared  as  heat.  For  instance,  in  the  melting 
of  ice,  all  that  portion  of  the  140  degrees  of  heat  which  are 
employed  in  melting  it  disappear  as  heat  entirely,  being 
converted  into  the  mysterious  force  necessary  to  hold  the 
water  in  a  state  of  liquefaction.  If  you  put  a  mass  of 
broken  ice  and  snow  over  a  hot  fire  in  a  kettle,  and  as  soon 
as  it  begins  to  melt  try  it  with  a  thermometer,  you  will 


A    CURIOUS    EXPERIMENT.  231 

find  it  at  32°.  Now  this  ice  may  take  several  hours  in 
melting,  during  which  time  a  great  quantity  of  heat  will 
pass  up  through  the  bottom  of  the  kettle,  namely,  as  many 
times  140  units  of  heat  as  there  are  pounds  of  ice  and 
snow ;  but  the  contents  of  the  kettle  will  not  be  warmed 
at  all  by  all  this  accession  of  heat.  If  you  put  a  thermom- 
eter in  again  at  the  moment  when  the  snow  and  ice  are 
all  melted,  you  will  find  it  still  at  32°.  That  enormous 
quantity  of  heat  has  disappeared  as  heat,  and  now  exists 
as  liquefying  force.  It  remains  there,  however,  still;  and 
it  must  all  be  taken  out  of  the  water,  being  reconverted 
into  heat  as  it  comes  out  again,  before  the  water  can  be 
frozen,  or,  rather,  while  it  is  in  the  act  of  being  frozen. 

There  is  a  very  striking  way  of  showing  that  heat,  when 
employed  in  the  work  of  liquefaction,  disappears  as  heat, 
by  an  experiment  which  Lawrence  performed  one  evening 
just  after  tea,  to  show  the  operation  of  the  principle  to  Al- 
mira  and  John,  and  also  to  some  other  persons  who  were 
there  at  the  time.  He  put  some  pieces  of  broken  ice  in  a 
tumbler,  sufficient,  as  he  estimated,  to  fill  it  about  one  third 
full  if  it  had  been  in  a  solid  piece.  Then  he  mixed  some 
hot  and  cold  water  in  another  tumbler,  pouring  in  first  a 
little  cold  and  then  a  little  hot,  and  trying  the  temperature 
with  a  small  pocket  thermometer  which  he  had,  until  he 
had  made  a  mixture  sufficient  to  fill  the  second  tumbler 
a  third  full  with  water  at  about  170°.  Water  at  170°  is 
quite  hot;  at  212°  it  is  boiling  hot. 

He  tried  his  thermometer  in  the  ice,  and  found  it  was 
at  32°. 

He  then  poured  the  warm  water  into  the  ice,  and  began 
stirring  it  with  a  spoon.  The  ice,  of  course,  began  imme- 
diately to  be  melted  by  the  hot  water. 

"Now,"  said  Lawrence,  "the  water  being  so  hot,  and  the 
ice  at  32°,  one  would  suppose  that  the  mixture,  after  the 


232  FORCE    CONVERTED    INTO    HEAT. 

ice  is  melted,  would  be  somewhere  between  the  two.  But, 
as  the  water  is  only  140°  above  the  ice,  which  is  at  the  rate 
of  140  units  of  heat  to  the  pound,  it  will  only  furnish  just 
heat  enough  to  liquefy  the  ice,  without  warming  it  at  all ; 
and  if  the  experiment  had  been  performed  with  precision 
— that  is,  if  the  proportions  had  been  exactly  right,  and  if 
I  could  have  adopted  any  means  to  prevent  the  operation 
from  being  affected  by  the  air  of  the  room — the  mixture, 
after  all  the  ice  was  melted,  would  not  be  any  warmer  than 
the  ice  itself  was  before,  notwithstanding  all  the  hot  water 
which  had  been  added  to  it." 

Lawrence  then  tried  his  thermometer  in  the  mixture  as 
soon  as  all  the  ice  had  disappeared,  and  found,  as  he  had 
said,  that  the  mixture  was  still  as  nearly  as  possible  at  32°. 

Such  an  experiment  as  this  shows,  in  a  very  striking 
manner,  that  the  heat  which  is  employed  in  melting  ice 
disappears  entirely  as  heat,  and  assumes  the  character  of 
force  of  liquefaction. 

It  is  the  same  when  water  is  boiled  and  steam  is  made, 
only  a  much  greater  quantity  of  heat  is  required  for  va- 
porization than  for  liquefaction.  But  all  that  wrhich  is  so 
employed  disappears  as  heat  entirely.  It  requires  about 
1000  units  of  heat  for  every  pound.  This  is  considerably 
more  than  enough  to  make  the  water  red  hot,  if  it  could  be 
employed  in  the  work  of  making  it  hot.  But  it  does  not 
heat  it — that  is,  it  does  not  raise  the  temperature  at  all. 
The  water  was  212°  when  it  began  to  boil,  and,  after  a 
thousand  units  of  heat  have  been  poured  into  it  from  the 
fire,  the  steam  resulting  is  just  at  212°,  as  the  water  was 
before. 

Thus  all  the  heat  produced  by  the  combustion  of  the  coal 
in  the  immense  furnaces  of  the  steamer  disappears  entirely 
as  heat,  so  far  as  it  is  expended  in  making  steam.,  and  then 
a  still  farther  proportion  of  it  disappears  as  heat  in  being 


LIQUEFYING    FORCE.  233 

employed  to  increase  the  tension  of  the  steam  and  drive  the 
engines.  If  the  heat  so  converted  into  force  were  to  con- 
tinue as  heat  in  the  ship,  it  would  become  entirely  unman- 
ageable. 

In  view  of  these  truths,  consider  what  an  enormous 
quantity  of  heat  is  stored  in  the  liquefying  force  of  the 
water  of  the  sea,  all  of  which  would  have  to  be  withdrawn 
in  some  way  before  the  sea  could  be  frozen.  This  is  one 
of  the  reasons  why  the  water  in  the  sea  and  in  great  rivers 
makes  such  slow  progress  in  becoming  frozen,  even  in  the 
coldest  weather. 

In  a  subsequent  conversation  with  Almira,  Lawrence  ex- 
plained that  the  converse  of  the  above  principle  was  true 
— namely,  that  as,  when  heat  is  made  to  develop  moving 
force,  it  ceases  to  exist  as  heat,  so,  when  moving  force,  or 
mechanical  force,  as  it  is  sometimes  called,  is  extinguished, 
a  precisely  equivalent  amount  of  heat  reappears. 

"  If  a  bullet  is  fired  from  a  musket  against  a  solid  wall," 
he  said,  "  the  heat  which  is  developed  by  the  extinction  of 
the  motion  would  be  sufficient,  it  is  calculated,  to  melt  the 
bullet,  if  it  could  all  be  concentrated  in  the  bullet  instead 
of  being  divided  between  the  bullet  and  the  wall." 

"Then  I  should  think,"  said  Almira,  "that  a  cannon  ball, 
when  it  strikes,  would  give  out  a  very  intense  heat." 

"It  does  so,"  said  Lawrence.  "It  produces  a  vivid  flash 
of  light  when  it  strikes  a  wall  of  masonry,  or  the  iron-clad 
side  of  a  ship,  in  a  dark  night.  It  is  the  same  in  all  cases 
of  the  extinguishment  of  motion,  or  of  the  partial  extin- 
guishment of  it,  as,  for  example,  in  friction.  When  one 
strikes  a  flint  and  steel  together,  a  part  of  the  force  of  the 
stroke  is  extinguished  by  the  friction,  and  that  portion  is 
converted  into  heat,  and  the  heat  thus  developed  is  suffi- 
cient to  ignite  the  small  shaving  of  steel  which  is  cut  off 
by  the  sharp  edge  of  the  flint.  So  in  all  cases.  If  you  rub 


234  FOECE    CONVEKTED    INTO    HEAT. 

your  finger  gently  upon  a  table,  just  so  far  as  the  force  you 
use  is  extinguished  by  the  friction,  so  far  a  precisely  equiv- 
alent amount  of  heat  is  developed.  The  rubbing  of  sleigh- 
runners  on  the  pavements  in  a  city,  or  on  the  ground  in  a 
country  road,  when  the  snow  is  so  thin  that  the  runners 
can  cut  through  to  the  pavement  or  to  the  ground,  makes 
the  snow  along  the  roadway  melt  much  faster  than  it  does 
at  the  sides.  The  result  is,  no  doubt,  affected  by  the  oper- 
ation of  another  cause,  but  the  friction  and  the  blows  of 
the  horses'  feet  have  a  great  effect  in  developing  the  heat 
which  melts  the  snow.  The  muscular  force  of  the  horses 
is  converted  into  heat  along  the  road  by  the  arrest  and  ex- 
tinguishment of  motion  in  the  friction  and  percussion. 

"  When  a  runner  moves  over  solid  or  continuous  ice  or 
snow,  the  friction  is  very  small,  and  then  the  force  of  the 
horses  is  no  longer  expended  in  warming  the  gravel  and 
the  ground,  and  so  takes  effect  to  a  greater  extent  in 
drawing  the  load.  The  same  result  is  attained  through 
contrivances  to  diminish  the  friction  by  other  means.  In 
Paris  the  roadway  in  the  streets  is  so  smooth — often,  where 
they  are  formed  of  asphalt,  as  smooth  and  hard  as  a  floor 
— and  the  mechanism  of  the  wheels  is  so  perfect,  and  is 
kept  in  such  perfect  condition,  that  the  omnibuses  are 
made  two  stories  high,  and  two  horses  are  able  to  draw, 
including  conductor  and  driver,  a  load  of  thirty  persons 
at  a  rapid  trot. 

"  It  is  very  interesting  to  observe,  too,"  continued  Law- 
rence, "that  the  same  phenomena  of  the  conversion  offeree 
into  heat  is  observed  in  the  case  of  liquids.  All  motion  of 
water  is  attended  with  friction,  and,  so  far  as  the  motion  is 
extinguished  by  this  cause,  heat  appears  in  its  place.  A 
river  warms  the  sands  on  its  banks  just  in  proportion  as 
its  motion  is  aroused  or  impeded  by  its  friction  against 
them  in  its  flow." 


„•*» 
•./   V," 


WAVES    OF    THE    SEA. 


237 


"  And  the  sea  ?"  suggested  Almira. 

"It  must  be  the  same  with  the  sea,"  said  Lawrence. 
"  Joule,  in  his  celebrated  experiments  for  determining  the 
mechanical  equivalents  of  heat,  showed  very  clearly  not 
only  that  the  agitation  of  water  produced  heat,  but  meas- 
ured very  exactly  the  amount  of  heat  produced.  And  so 
the  waves  of  the  sea,  so  far  as  the  force  with  which  they 
move  is  arrested,  or  retarded,  or  extinguished  in  any  way  by 
the  friction  of  the  water  upon  itself,  or  by  the  beat  of  the  bil- 
lows on  the  rocks  upon  the  shore,  must  have,  on  the  whole, 
a  vast  effect  in  raising  the  temperature  of  the  whole  mass. 

"  The  fall  of  water  in  a  cataract  must  develop  a  large 


THE    WATERFALL   (NEVADA    FALL). 


238  FOKCE    CONVERTED    INTO    HEAT. 

quantity  of  heat.  The  precise  amount  might  be  calculated 
by  knowing  the  quantity  of  water  that  falls  in  a  given 
time,  and  the  height.  The  heat  thus  produced  by  the  ex- 
tinguishment of  motion  has  an  effect  in  producing  the 
mists  and  fogs  which  rise  from  below. 

"It  is  so  in  all  cases  of  friction  or  arrested  motion  in 
water,"  added  Lawrence. 

"  And  when  we  stir  water  with  a  spoon  in  a  cup  ?"  said 
Almira. 

"  We  warm  it,"  said  Lawrence, "  so  far  as  we  produce 
friction  and  consequent  extinguishment  of  moving  force 
among  the  particles." 

"My  tea  always  grows  colder  when  I  stir  it,"  said  Flip- 
py, who  happened  to  be  listening  to  this  part  of  the  con- 
versation. 

"  True,"  said  Lawrence,  "but  that  is  because  the  tea,  when 
it  is  hotter  than  the  air  around  it,  loses  heat  in  other  ways 
faster  than  it  gains  it  from  the  friction.  The  very  stirring 
itself  makes  it  cool  faster  by  bringing  fresh  portions  to  the 
surface  in  contact  with  the  cool  air.  It  is  only  so  far  as 
moving  force  among  the  particles  of  tea  is  extinguished  by 
the  friction  that  any  heat  is  developed,  and  this  is  very 
small — very  small  indeed,  but  it  is  none  the  less  real. 

"  So  it  is,"  continued  Lawrence, "  with  all  the  motions 
which  take  place  in  any  way  in  the  world  around  us.  So 
far  as  any  such  motion  is  extinguished,  it  is  converted  into 
heat." 

"  A  flake  of  snow,  for  example,"  said  Almira, "  falling 
through  the  air  gently  and  alighting  upon  the  snow  which 
fell  before  it." 

"  Yes,"  rejoined  Lawrence,  "  that  is  an  excellent  exam- 
ple. So  far  as  the  flake  in  falling  puts  particles  of  the  air 
in  motion  on  its  way,  its  moving  force  is  not  extinguished, 
but  only  transferred,  and  no  heat  is  produced.  But  so  far 


EFFECT  OF   FKICTION.  239 

as  there  is  any  friction  between  it  and  the  particles  of  air, 
if  there  is  any  such,  so  far  its  moving  force  is  undoubtedly 
converted  into  heat.  So  that,  in  fact,  if  there  is  such  fric- 
tion, the  flake  warms  the  track  through  the  air  through 
which  it  falls,  and  when  it  strikes  the  ground  it  warms 
slightly  the  spot  where  it  falls. 

" Of  course,  I  mean  by  the  word  warms"  added  Law- 
rence, "  that  it  makes  it  less  cold.  The  effect  is  infinitesi- 
mally  small — wholly  inappreciable  by  any  test  that  we  can 
apply,  and  of  no  use  to  be  taken  into  account  in  any  way 
except  as  a  means  of  enabling  us  to  receive  a  just  and  full 
comprehension  of  the  universality  of  the  law  of  correlation 
between  heat  and  mechanical  force." 


240  THE    THERMOELECTRIC   MULTIPLIER. 


CHAPTER  XXV. 

THE    THERMO-ELECTRIC   MULTIPLIER. 

ALTHOUGH  it  would  not  be  possible  to  measure  or  even 
to  find  sensible  evidences  of  the  heat  developed  by  the 
fall  of  a  snow-flake  on  the  snow  that  fell  before  it,  there  is 
a  method  which  has  been  discovered,  and  is  in  use  among 
scientific  men,  for  measuring  astonishingly  minute  changes 
of  temperature — as  small,  in  fact,  as  one  or  two  thousandth 
part  of  a  degree  of  the  Fahrenheit  thermometer !  The 
very  delicate  instrument  by  which  it  is  effected  is  called 
Melloni's  Thermo-electric  Multiplier. 

In  the  common  thermometer  the  changes  in  temperature 
are  made  manifest  by  the  power  of  heat  to  expand  sub- 
stances— that  is,  to  increase  their  bulk.  In  this  instru- 
ment the  effect  depends  upon  the  power  to  set  in  motion, 
under  certain  circumstances,  a  current  of  electricity.  It  is 
found  that  if  two  metals — bismuth  and  antimony  are  the 
most  effective  for  the  purpose — are  joined  together,  and 
the  junction  is  warmed,  a  feeble  current  of  electricity  is  set 
in  motion  from  one  to  another;  and  if  several  pairs  are 
made,  and  the  heat  is  applied  to  the  junctions  on  one  side, 
the  force  of  the  several  currents  is  accumulated.  The  en- 
graving, Fig.  1,  on  the  opposite  page,  shows  the  principle 
of  the  arrangement,  where  the  bars  A  are  the  bars  of  anti- 
mony, and  the  bars  B  those  of  bismuth,  the  arrow  showing 
the  direction  of  the  electric  current. 

Many  pairs  of  these  bars  are  formed,  and  the  whole 
packed  together  in  a  compact  manner  in  a  case,  as  shown 
in  Fig.  2.  The  two  wires  at  the  top  are  connected,  the  one 


DELICATE    TEST    OF    HEAT. 


241 


Fig.  1. 


MELLONl'S   THERMO-ELEOTKIO   MULTIPLIER. 

with  the  bismuth  and  the  other  with  the  antimony  end  of 
the  system,  and  it  is  through  a  wire  joining  these  that  the 
current  of  electricity  is  to  flow  when  the  apparatus  is  in 
use. 

In  Fig.  3,  one  of  the  instruments  is  shown  as  arranged 
for  use.  The  case  formed,  as  above,  of  bars  of  metal  (P),  is 
mounted  on  the  stand.  The  two  wires  in  this  instrument, 
represented  as  coming  out  at  the  side,  are  connected  respect- 
ively with  the  two  electric  poles  of  the  system.  The  ar- 
rows show  the  course  which  the  electricity  is  supposed  to 
take  through  the  wires  «5,the  ends  of  which  are  held  firmly 
in  contact  with  the  poles  of  the  instrument  by  the  binding 
screws  at  P.  The  middle  part  of  the  wire  is  carried  into 
the  lower  part  of  the  instrument  (G),  where  it  is  wound 

L 


242  THE    THERMO-ELECTRIC    MULTIPLIER. 

many  times  round  a  little  frame,  so  as  to  form  a  flat  coil, 
by  which  the  effect  of  the  current  is  multiplied  many  times, 
and  is  made  to  deflect  a  fine  needle  in  proportion  to  the 
increase  of  temperature  produced  at  the  junctions  of  the 
metals  in  the  case  at  P.  C  is  a  metallic  cone,  with  the  in- 
side surface  blackened,  to  regulate  the  quantity  of  radiated 
heat  allowed  to  reach  and  act  upon  the  instrument. 

This  general  description  will  give  a  sufficient  idea  of  the 
principle  on  which  the  instrument  operates,  which  is  all 
that  is  necessary  for  our  present  purpose. 

With  this  instrument  a  great  number  and  variety  of  ex- 
periments have  been  made,  and  a  great  many  truths  dis- 
covered, which  have  vastly  extended  the  knowledge  we 
possess  of  the  action  of  heat  in  the  general  economy  of  na- 
ture, inasmuch  as  extremely  minute  changes  of  tempera- 
ture can  be  made  perceptible,  and  even  be  measured  by  it 

One  very  curious  and  important  service  performed  by 
means  of  it  was  to  determine,  by  another  method,  the  me- 
chanical equivalent  of  heat,  which  Joule  had  already  ob- 
tained by  means  of  the  friction  of  water.  By  this  new 
method  a  small  stream  of  mercury  was  allowed  to  fall 
from  a  known  height  into  a  jar  of  mercury  on  the  floor 
below.  From  the  quantity  of  mercury  which  fell,  and  the 
height  through  which  it  descended,  the  quantity  of  force 
expended  or  extinguished  in  the  jar  was  known,  and  by 
this  instrument,  the  thermo-electric  multiplier,  the  exact 
amount  of  the  increase  of  temperature  of  the  mercury  in 
the  jar  was  ascertained. 

The  same  point  has  also  been  determined  by  experiments 
made  on  a  great  scale  in  a  large  machine-shop  at  a  place 
called  Hogelbach,  on  the  Rhine,  in  Germany,  by  Mr.  Him, 
one  of  the  partners  in  the  firm.  He  used  a  steam  engine 
of  100-horse  power  for  his  experiments,  and  performed 
them  with  the  greatest  care  and  attention,  and  at  no 


LAWRENCE    AND    ALMIRA.  243 

small  expense.  He  succeeded  in  confirming,  by  experi- 
ments on  this  great  scale,  the  results  which  had  been  pre- 
viously obtained  from  the  action  of  small  quantities  of 
heat.  He  showed,  first,  that  in  working  his  engine,  a  con- 
siderable portion  of  the  heat  which  was  produced  by  the 
combustion  of  the  coal  entirely  disappeared ;  and,  second- 
ly, that  the  amount  of  mechanical  motion  produced  by  the 
engine — that  is,  of  work  done  by  it — corresponded  exactly 
to  the  amount  of  heat  which  had  disappeared,  in  the  pre- 
cise proportion  which  had  been  ascertained  by  Joule  and 
other  experimenters — namely,  for  English  measurements, 
one  unit  of  heat  to  772  foot-pounds  of  work. 

I  will  repeat  my  recommendation  that  every  reader  of 
this  book  should  fix  the  principle,  and  the  numerical  state- 
ment of  it,  as  above,  firmly  in  his  mind,  inasmuch  as  this 
principle — that  heat  can  be  changed  into  mechanical  force, 
and  mechanical  force  into  heat,  at  a  certain  fixed  and  de- 
termined rate,  is  regarded  as  one  of  the  greatest  discov- 
eries of  modern  times. 

One  day,  as  the  ship  in  which  Lawrence  and  his  friends 
were  making  their  passage  was  approaching  the  land,  the 
weather  was  so  cold  and  chilly  upon  deck  that  a  large 
number  of  the  passengers  had  gone  below.  Some,  how- 
ever, remained  in  sheltering  nooks  and  corners,  and  Law- 
rence, in  passing  along,  observed  Almira  seated  in  a  fold- 
ing chair  under  the  lee  of  one  of  the  great  chimneys. 
She  was  engaged  in  reading.  Lawrence  stopped  to  bid 
her  good-morning  as  he  passed,  and  she  at  once  closed  her 
book  and  looked  up  to  him  with  a  pleased  expression  of 
countenance,  which  led  him  to  imagine  that  perhaps  she 
would  like  to  have  him  remain  and  keep  her  company.  If 
she  had  kept  her  book  open  in  her  lap  in  responding  to  his 
salutation,  he  would  have  inferred  that  she  intended,  and 
so,  probably,  that  she  wished,  to  go  on  with  her  reading. 


244  THE    THERMO-ELECTRIC    MULTIPLIER. 

He  accordingly  brought  up  another  folding  chair  and 
sat  down  by  the  side  of  her.  They  talked  together  for 
some  time  about  various  subjects,  and  especially  about 
Switzerland,  where  Almira  had  never  been,  but  where  she 
was  now  going ;  and  she  was  much  interested  in  hearing 
the  explanations  which  Lawrence  gave  her  in  respect  to 
the  torrents,  the  glaciers,  and  the  avalanches  to  be  seen 
among  the  Alps,  which  explanations  would  enable  her 
much  better  to  understand  and  appreciate  these  and  the 
other  grand  phenomena  of  the  region  when  she  should 
come  to  see  them.  He  gave  her,  moreover,  an  account 
of  expeditions  which  he  had  made,  in  company  with  some 
other  travelers  and  a  party  of  guides,  among  the  higher 
Alps. 

I  should  be  very  glad  to  report  some  of  this  conversa- 
tion, but  mountains  and  glaciers  are  not  the  subject  of  this 
volume. 

At  length  John  and  Flippy  came  by. 

"  Ah  !"  said  Flippy,  "  here  is  a  good  warm  place."  So 
saying,  he  held  out  his  hands  toward  the  great  chimney 
to  warm  them.  The  radiation  from  the  chimney  was  very 
powerful,  like  that  from  a  gigantic  stove. 

"Let's  get  some  camp-stools  and  sit  down  here,"  said 
Flippy. 

"  Do,"  said  Almira ;  "  it  is  a  very  nice  place,  and  then 
Mr.  Lawrence  will  give  us  some  more  talk  about  heat." 

"  Yes,"  said  Lawrence ;  "  I'll  make  believe  that  you  are 
an  audience,  and  I  will  give  you  a  regular  lecture." 


A1>VEMTUKE8   AMONG   TUE   ALPS. 


A  SUPPOSITITIOUS   LECTURE.  247 


CHAPTER  XXVI. 

TRANSMISSION    OP    HEAT. 

So  the  boys  brought  camp-stools,  and  established  them- 
selves comfortably  under  the  shelter  of  the  chimney  and 
in  its  warmth,  and  then,  after  some  few  minutes  spent  in 
common  playful  conversation,  Lawrence  began. 

"Ladies  and  gentlemen, — This  is  to  be  a  lecture  of  hard 
words." 

"  You  can't  say  ladies  to  your  audience,"  interrupted 
Flippy, "  for  there  is  only  one." 

"  I  am  making  believe  that  it  is  a  large  audience,"  said 
Lawrence. 

"  Go  ahead,"  said  Flippy. 

"The  hard  words,"  continued  Lawrence,  speaking  in  a 
deliberate  and  oratorical  tone,  as  if  he  were  a  lecturer  ad- 
dressing an  assembly, "  relate,  all  but  one,  to  the  movement 
of  heat.  They  are  these  : 

"  Radiation,  Reflection,  Refraction,  Conduction,  Convec- 
tion, and  Attention. 

"I  shall  explain  what  these  words  mean,  and  if  any  of 
my  audience  forget  any  of  them,  or  the  meaning  of  them, 
they  will  not  be  able  to  pass  the  examination." 

"  Are  we  going  to  have  an  examination  ?"  asked  Flippy. 

"  Yes,"  said  Lawrence,  "  and  a  very  strict  examination 
too.  There  are  six  of  the  hard  words,  but  the  last  one  you 
will  not  have  to  study,  but  only  to  practice,  since  it  has 
nothing  to  do  with  heat,  but  only  means  that  you  must 
listen  attentively  to  what  I  say.  If  you  pay  close  atten- 
tion to  this  lecture,  I  will  give  another  some  day,  on  de- 
flagrations, detonations,  and  explosions." 


248  TRANSMISSION    OF    HEAT. 

"  Good  !"  said  Flippy,  clapping  his  hands ;  "  I  should  like 
to  hear  that  lecture.  Pll  attend." 

So  he  placed  himself  in  an  attitude  of  attention,  while 
Lawrence  proceeded : 

"  When  heat  shoots  out  from  any  hot  body  in  streams 
through  the  air,  or  through  space,  the  movement  is  called 
radiation.  The  streams  are  called  rays.  If  you  hold  up 
your  hand  opposite  this  chimney  you  will  feel  the  radia- 
tion from  it." 

Flippy  and  John  both  held  out  their  hands  to  verify  this 
statement. 

"  Radiation  is  practically  instantaneous,"  continued  the 
lecturer.  "  If  I  hold  a  book  in  the  way,  so  as  to  stop  the 
radiation  upon  your  hand,  and  then  suddenly  withdraw  it, 
you  will  feel  the  heat  shoot  across  to  your  hand  instantly, 
even  though  it  might  be  several  feet  off.  The  heat  arrives 
to  the  earth  from  the  sun  instantly,  as  soon  as  the  sun 
rises,  though  it  has  ninety  millions  of  miles  to  come  on  its 
way.  The  quantity  of  heat  that  is  radiated  from  the  sun 
upon  the  earth  every  day  is  enormous.  It  entirely  sur- 
passes the  power  of  the  human  imagination  to  conceive  of 
the  quantity.  A  great  portion  of  it  is  employed  in  warm- 
ing the  earth  and  the  air,  and  a  great  portion 'of  it  is  ex- 
pended in  the  leaves  of  trees,  being  there  changed  into 
force,  which  is  stored  up  in  the  wood,  and  peat,  and  coal, 
which  is  formed  from  it,  to  come  out  again  as  heat  in  the 
future  processes  of  combustion  and  decay.  So  don't  for- 
get what  radiation  is. 

"  The  next  word  is  reflection.  If  radiated  heat  strikes 
against  a  glass,  or  any  polished  surface,  and  it  is  the  same, 
to  some  degree,  with  surfaces  that  are  not  polished,  it  is  in 
part  reflected — that  is,  it  is  made  to  bound  back  like  a  ball 
thrown  against  a  wall. 

"When  you  let  a  sunbeam  shine  upon  a  piece  of  looking- 


REFLECTION.  249 

glass,  by  turning  the  glass  you  can  turn  the  beam  of  light 
in  any  way  you  choose.  That  is  reflection.  It  is  reflec- 
tion of  light.  When  you  reflect  the  light  of  a  sunbeam  in 
this  way,  you  reflect  the  heat  too.  We  do  not  see  the  heat 
as  we  do  the  light,  but  it  is  there. 

"  If  the  mirror  that  reflects  the  heat  is  concave,  then  it 
will  reflect  it  in  such  a  manner  as  to  gather  all  the  rays  to 
one  spot,  called  the  focus,  and  if  you  hold  any  combustible 
substance  there  it  will  be  set  on  fire,  showing  that  the  heat 
has  been  concentrated  in  one  point  by  reflection  from  the 
concave  mirror. 


EFFECT   OF   THE    OONCAVE   KEFLEOTOE. 


"  There  is  a  story  told  of  a  philosopher  in  ancient  times 
who  set  a  fleet  of  the  enemy  on  fire  by  reflecting  heat  from 
the  sun,  by  a  great  many  mirrors,  against  the  side  of  one 
of  the  ships.  Each  mirror  reflected  a  portion  of  heat,  and 
all,  united  together,  set  the  wood  on  fire.  I  have  some 

L2 


250  TRANSMISSION    OF    HEAT. 

doubt,  however,  whether  the  story  is  true.  Some  experi- 
menters once  undertook  to  heat  water,  and  even  to  cook, 
by  concentrating  the  reflected  heat  of  the  sun  upon  some 
kind  of  vessel. 


COOKING  BY  THE  BEFLEOTED  HEAT  OF  THE  6UN. 

"  At  any  rate,  continued  Lawrence,"  heat,  like  light,  may 
be  reflected — that  is,  turned  back  from  its  course  by  a  mir- 
ror or  a  reflector  of  any  kind.  It  may  also  be  bent  out  of 
its  course  in  passing  through  a  transparent  substance  like 
glass. 

"  This  bending  of  the  rays  of  light  in  passing  through  a 
transparent  substance  is  refraction,  which  is  the  third  of 
the  words  that  you  have  to  remember. 


REFRACTION.  251 

"  There  is  a  kind  of  glass,  thicker  in  the  middle  than  at 
the  edges,  which  is  called  a  convex  lens." 

So  saying,  Lawrence  drew  from  his  pocket  a  small  mag- 
nifying glass,  and  let  his  audience  all  see  that  it  was  thicker 
in  the  middle  than  at  the  edges. 

"Now,  if  the  rays  from  the  sun  pass  through  this  lens,  la- 
dies and  gentlemen,"  continued  Lawrence, "  the  outer  ones 
would  be  turned  inward  toward  the  central  ones,  each 
being  turned  just  in  proportion  to  its  distance  from  the 
centre,  so  that  they  will  all  meet  at  a  point*  called  the 
focus.  You  can  see  the  focus  of  light,  and  if  you  let  me 
throw  the  focus  upon  the  back  of  your  hand,  you  will  feel 
the  focus  of  heat." 

This  Lawrence  did  to  Flippy,  and  Flippy  felt  the  heat 
very  sensibly. 

"  It  is  what  they  call  a  sun-glass,"  said  Flippy. 

"Such  a  lens,  ladies  and  gentlemen,"  continued  Law- 
rence, appearing  not  to  notice  Flippy's  remark,  "  is  some- 
times called  a  sun-glass ;  and  if  it  is  large  and  of  a  true 
form,  and  if  the  sun  shines  bright,  the  heat  concentrated 
by  it  will  be  sufficient  to  set  paper  or  cloth  on  fire.  Boys 
sometimes  flash  gunpowder  with  it. 

"  The  next  word,"  continued  Lawrence,  going  on  with 
his  lecture,  "  is  conduction.  Conduction  is  when  heat,  in- 
stead of  shooting  swiftly  through  space  with  great  veloci- 
ty, creeps  along  through  any  substance  from  particle  to 
particle.  If  you  put  a  flat-iron  upon  a  hot  stove  and  hold 
it  there  with  your  hand,  at  first  you  will  feel  the  heat  that 
comes  from  the  stove  by  radiation  on  the  outside  of  your 
hand.  But  the  handle  of  the  flat-iron  will  feel  cool  to  the 
palm  of  the  hand,  and  to  the  fingers  that  clasp  it,  until  the 
heat  has  had  time  to  creep  along  slowly  through  the  sub- 
stance of  the  iron  itself,  and  after  a  time  it  will  become  so 
hot  that  you  can  not  hold  it.  Heat  creeps  more  easily  and 


252 


TRANSMISSION    OF    HEAT. 


EFFECT  OF  THE  CONVEX  LENS. 


rapidly  through  the  substance  of  iron  than  it  does  through 
many  other  substances.  There  is  an  experiment  by  which 
a  gradual  progress  of  the  heat  may  be  made  very  plain  to 
the  eye. 


CONDUCTION   OF  HEAT. 


"You  take  a  bar  of  iron,  and  support  it  on  a  stand  hori- 
zontally, so  that  you  can  heat  one  end  of  it  by  a  spirit 


CONDUCTION.  253 

lamp.  There  are  a  number  of  holes  in  the  upper  side  of 
the  bar,  in  each  of  which  a  short  wire  is  placed,  the  wires 
having  been  coated  with  wax  by  being  dipped  into  melted 
wax  beforehand.  Here  you  see  the  apparatus  itself." 

So  saying,  Lawrence  took  out  a  piece  of  paper,  and  made 
a  sketch  showing  the  form  and  arrangement  of  the  appa- 
ratus, with  the  wax  melted  at  different  heights  along  the 
tube,  as  the  heat  conducted  along  the  iron  reached  them 
in  succession. 

"Some  substances  conduct  the  heat  very  readily  and 
rapidly,  and  others  very  slowly,"  continued  the  lecturer. 
"  Iron  and  most  of  the  metals  are  good  conductors ;  glass, 
ivory,  wood,  and  air  are  very  bad  conductors.  I  will  show 
you  the  difference  between  a  rod  of  iron,  which  is  a  good 
conductor,  and  a  pipe-stem,  which  is  a  very  bad  one." 

So  saying,  Lawrence  took  John's  hands  and  put  them 
together  as  if  he  wished  to  make  a  receptacle  to  hold 
something. 

"  Here  you  see  a  bowl,"  he  continued ;  "  I  am  going  to 
pour  some  boiling  water  into  it." 

So  saying,  he  made  believe  pour  water  into  the  hollow 
which  he  had  made  by  John's  hands. 

"  Now,"  said  he,  "  I  will  put  a  rod  of  iron  and  also  a 
pipe-stem  in  the  water,  leaving  the  upper  ends  projecting 
out  of  the  water  by  the  edge  of  the  bowl." 

So  saying,  he  put  his  pencil-case  into  the  bowl,  and  also 
his  knife,  pretending  that  the  pencil-case  was  the  pipe-stem 
and  the  knife  was  the  iron  rod,  and  then  asked  Flippy,  as 
one  of  the  audience,  first  to  touch  the  end  of  the  pipe-stem, 
and  then  the  end  of  the  iron  rod,  to  see  how  cool  the  former 
arid  how  hot  the  latter  was,  on  account  of  the  difference  in 
the  conducting  power  of  the  two  in  bringing  up  the  heat 
from  the  water.  Flippy  entered  into  the  idea  very  readily. 
He  felt  of  the  end  of  the  pencil  once  or  twice,  with  an  ex- 


254  TRANSMISSION    OF    HEAT. 

pression  on  his  countenance  as  if  it  was  quite  cool.  He 
then  touched  the  end  of  the  knife,  but  at  once  pulled  his 
hand  away,  and  began  to  blow  his  fingers  as  if  he  were 
burnt.  Almira  smiled  at  this  novel  mode  of  giving  exper- 
imental illustrations  of  philosophical  principles,  while  John 
laughed  outright. 

"  When  we  wish  to  stop  the  flow  of  heat  by  conduction," 
continued  Lawrence,  "  we  put  bad  conductors  in  the  way 
to  intercept  it.  They  fit  a  small  piece  of  ivory  or  wood  at 
the  upper  and  lower  ends  of  the  handles  of  tea-pots  and 
coffee-pots,  to  prevent  the  heat  flowing  too  fast  into  the 
handle ;  and  loose  substances  filled  with  air,  such  as  wool- 
en cloths,  over  our  bodies,  to  keep  the  heat  from  passing 
out ;  and  the  same  things,  or  straw  and  shavings,  around 
ice,  to  keep  the  heat  from  getting  in.  Such  things  keep 
the  heat  from  passing  either  way.  There  is  no  warmth  in 
the  substances  themselves ;  they  only  keep  what  warmth 
there  is  on  one  side  or  the  other  of  them  from  passing 
through. 

"The  next  word  in  my  lecture,"  said  Lawrence,  "is  con- 
vection. Convection  means  the  act  of  conveying,  and  this 
is  the  kind  of  motion  of  heat  which  takes  place  when  the 
heat  does  not  pass  through  the  substance  of  itself  from 
particle  to  particle,  while  the  particles  themselves  remain 
at  rest,  but  when  the  particles  themselves  move,  and  so  con- 
vey it  with  them.  It  is  in  this  way  the  heat  is  diffused 
through  water.  When  you  heat  water  in  a  kettle  over  a 
fire,  the  heat  does  not  pass  up  of  itself  through  the  sub- 
stance of  the  water,  as  it  does  through  the  substance  of 
iron,  but  the  particles  that  are  on  the  bottom  get  hot,  and 
then  they  move  up  in  currents  through  the  cold  water 
above,  and  that  comes  down  and  gets  hot  in  its  turn,  and 
so,  finally,  it  all  gets  hot.  This  is  the  way  that  heat  is  dif- 
fused through  the  ocean  and  through  the  air,  by  warm  cur- 


RADIATING    SURFACES.  255 

rents  of  water  and  of  air  that  circulate  through  the  whole 
mass  and  carry  the  heat  every  where.  Every  warm  breeze 
from  the  south  is  a  current  of  convection,  and  so  is  every 
warm  current  in  the  sea.  The  Gulf  Stream  is  probably 
the  grandest  example  of  a  current  of  convection,  and  of 
the  diffusion  of  heat  by  that  method,  on  the  globe. 

"  And  this  is  the  last  of  the  five  words  relating  to  the 
modes  of  movement  of  heat,  namely,  radiation,  reflection, 
refraction,  conduction,  and  convection,  and  this  finishes 
my  lecture." 

There  were  many  other  things  that  Lawrence  would 
have  liked  to  explain  in  his  lecture  in  respect  to  the  five 
modes  of  movement  observable  in  heat,  but  he  noticed  that 
the  officers  were  upon  the  quarter-deck  with  their  sextants, 
and  he  knew  that  they  might  at  any  time  make  it  twelve 
o'clock,  when  the  bell  would  be  immediately  rung  for 
luncheon.  There  was  one  thing  in  respect  to  radiation 
that  he  did  not  have  time  to  explain,  which  is  very  im- 
portant— namely,  that  when  heat  radiates  from  a  body, 
the  quantity  thus  issuing  from  it  depends  not  only  upon 
the  temperature  of  the  body — that  is,  upon  the  internal 
condition  as  to  heat — but  also  upon  the  nature  of  the  sur- 
face from  which  the  radiation  takes  place.  The  heat  ra- 
diates much  more  rapidly,  for  example,  from  a  rough  or  a 
dull  surface  than  from  a  bright  or  a  polished  one.  It  is 
affected,  too,  very  much  by  the  nature  of  the  material  of 
which  the  body  is  composed. 

The  laws  in  relation  to  the  effect  of  surface  on  radiation 
have  been  very  carefully  determined  by  the  aid  of  a  simple 
contrivance  called  Leslie's  Cube. 

The  principle  of  this  device  is  illustrated,  in  one  form,  by 
a  cubical  vessel  of  tin,  the  sides  of  which  are  in  different 
conditions.  One  side  is  left  polished,  another  is  roughened 


256 


TRANSMISSION    OF    HEAT. 


by  sand-paper,  a  third  blackened  with  lamp-smoke.     The 
cube  is  filled  with  water  and  put  over  a  lamp,  a  slender 
tube  being  open  above  to  allow  of  the  escape  of  the  steam. 
Of  course,  all  the  four  sides  of  the  cube  will  be  equally 
hot,  but  there  will  be  found  to  be  a 
very  great  difference  in  the  amount 
of  radiation  from  them. 

By  means  of  cubes  of  this  kind,  in 
connection  with  the  thermo-electric 
multiplier,  by  which  very  slight  dif- 
ferences in  the  radiation  can  be  meas- 
ured, the  whole  subject  has  been  very 
fully  investigated,  and  many  facts 
have  been  ascertained  which  are  of 
great  use  to  engineers,  mechanics, 
and  constructors  of  apparatus  of  all 
kinds  in  which  heat  is  concerned. 
LESLIE'S  cu«E.  ^Q  know,  without  much  nice  obser- 

vation, that  a  tea-pot,  in  order  to  prevent  the  radiation  of 
the  heat,  and  to  keep  the  tea  hot,  must  be  bright  and  pol- 
ished on  the  outside,  while  a  stove  or  a  stove-pipe,  in  order 
to  facilitate  the  delivery  of  the  heat  developed  by  the  com- 
bustion within,  must  be  dull  in  surface,  and  is  all  the  bet- 
ter for  being  black. 

Lawrence  might  have  included  among  the  subjects  con- 
nected with  the  transmission  of  heat,  which  he  discussed 
in  his  lecture,  that  of  absorption,  which  would  have  been 
another  hard  word  for  Flippy,  and  which  refers  to  the  re- 
ceiving of  heat  by  the  surface  of  any  substance  upon  which 
it  is  projected  by  radiation,  and  to  its  being  taken  in,  or 
absorbed,  by  the  substance  itself.  The  character  of  the 
surface  affects  the  amount  of  absorption  very  much  as  it 
does  the  radiation,  as  is  shown  by  the  common  experiment, 
easily  performed,  of  putting  bits  of  different  colored  cloth 


NOON  GUN  OF  THE  PALAIS  ROYAL.         257 

upon  the  snow  on  a  bright  spring  morning,  and  observing 
how  much  faster  and  how  much  deeper  some  melt  their 
way  down  into  the  snow  than  others. 

He  did  not  have  time  to  enter  into  these  topics,  but,  be- 
fore dismissing  his  audience,  he  asked  the  boys  some  ques- 
tions by  way.  of  examining  them  on  the  subject  of  the  lec- 
ture, and  when  they  came  to  refraction,  and  to  the  phe- 
nomenon of  the  rays  of  heat  being  brought  to  a  focus  by 
passing  through  a  convex  lens,  he  gave  them  an  account 
of  a  small  cannon  which  he  said  there  used  to  be  in  the 
garden  of  the  Palais  Royal,  in  Paris,  with  a  lens  fixed 
above  it  in  such  a  position  that  precisely  at  noon  the  focus 
of  the  lens  should  come  over  the  powder  at  the  touch-hole 
and  fire  the  gun,  thus  giving  notice  to  all  the  people  in  all 
the  shops,  and  restaurants,  and  galleries  around  that  it  was 
noon — that  is,  noon  by  solar  time. 


THE  NOON  GUN  OF  THE  PALAIS  KOYAL. 


Just  as  the  party  had  reached  this  point  in  Lawrence's 
explanation,  eight  bells  were  struck  at  the  quarter-deck, 
and  the  officers  went  below  with  their  sextants.  The  strik- 
ing of  eight  bells  was  immediately  repeated  on  the  forward 


258  TRANSMISSION    OF    HEAT. 

deck,  and  a  moment  afterward  the  bell  announcing  lunch 
was  rung  below.  Flippy  said  he  was  sorry,  as  he  wished 
to  hear  about  explosions,  but  Lawrence  promised  to  tell 
him  about  that  at  some  future  time. 

"  Only,"  said  he,  "  we  can  not  have  illustrative  experi 
ments  for  a  lecture  on  that  subject  at  sea,  as  the  only  ex- 
plosion to  be  thought  of  on  board  a  steamer  is  the  burst- 
ing of  the  boiler,  an  illustration  of  the  subject  which  I 
hope  we  shall  be  spared." 


EXPLOSIONS.  259 


CHAPTER  XXVII. 

SCIENTIFIC   TEEMS    EXPLAINED, 

THERE  are  a  great  many  very  remarkable  things  con- 
nected with  the  characteristics  and  the  action  of  heat  in 
the  economy  of  nature  which  would  require  a  great  deal 
of  study  to  comprehend  in  all  their  bearings  and  relations, 
but  which,  in  respect  to  the  general  principles  involved, 
are  easily  enough  understood.  One  of  these  things  is  the 
philosophy  of  explosions. 

EXPLOSIONS. 

Explosions,  so  far  as  they  are  produced  by  the  sudden 
evolution  of  heat  by  combustion — which  are  all  that  we 
have  to  do  with  in  this  volume — are  effected  simply  by  the 
rapidity  with  which  the  process  of  combustion  is  carried 
on.  When  the  combustion  is  extremely  rapid,  but  not  sen- 
sibly instantaneous,  we  call  it  a  deflagration ,  as,  for  exam- 
ple, when  gunpowder  is  burned  in  the  open  air.  We  call 
it  an  explosion  when  the  combustion  and  the  force  which 
the  heat  develops  are  sensibly  instantaneous,  as  when  gun- 
powder is  burned  under  pressure  by  means  of  which  the 
heat  developed  by  the  first  portions  burnt  takes  effect  in- 
stantly in  igniting  the  rest,  and  so  hastens  the  whole  pro- 
cess. 

Now,  combustion  being  only  a  violent  chemical  action, 
consisting  usually  of  the  combination  of  carbon  or  hydro- 
gen with  oxygen,  the  rapidity  of  it  depends  mainly  upon 
how  readily  the  carbon  or  the  hydrogen  finds  oxygen  at 
hand  to  combine  with  it.  If  you  lay  a  log  of  dry  wood 
on  the  fire,  it  burns  slowly,  because  the  inner  portions  of 


2 GO  SCIENTIFIC   TERMS    EXPLAINED. 

it  are  shut  out  from  the  access  of  oxygen,  and  can  only  be 
reached  by  it  as  fast  as  the  outer  portions  are  burnt  away, 
and  they  can  be  burnt  away  only  so  fast  as  they  can  derive 
oxygen  from  the  air.  You  can  hasten  the  process  by  send- 
ing air  in  more  rapidly  by  blowing  the  fire,  and  you  could 
hasten  it  very  much  more  if  you  send  in  upon  it  a  stream 
of  oxygen,  instead  of  air,  of  which  the  oxygen  forms  but  a 
small  part.  Still,  even  in  this  case  the  inner  portions  could 
not  be  reached  by  the  oxygen  except  so  far  as  the  outer 
ones  were  burnt  away. 

But  if  now  we  divide  up  the  log  of  wood  into  shavings 
by  means  of  a  plane,  and  put  the  heap  of  shavings  on  the 
fire,  we  have  the  same  substance  as  before,  and  the  same 
process  of  combination  with  oxygen  to  go  on ;  but  it  will 
be  greatly  facilitated  now  by  the  oxygen  of  the  air  having 
much  more  easy  and  intimate  access  to  it  through  the  open- 
ings between  the  shavings,  and  the  finer  and  thinner  the 
shavings  are,  and  the  more  lightly  they  are  laid  together, 
the  more  rapid  the  combustion  will  be.  But  it  will  not  be 
instantaneous,  for  every  shaving,  however  thin,  has  some 
thickness,  and  the  interstices,  moreover,  will  not  contain 
oxygen  enough  for  a  full  supply. 

But  if,  instead  of  wood,  we  take  the  hydrogen  in  the 
form  of  a  gas,  and  mingle  it  with  air — or,  what  would  be 
still  better,  with  oxygen,  in  the  proper  proportions,  so  that 
each  particle  of  hydrogen  shall  have  the  oxygen  that  it  re- 
quires close  at  hand — then  the  combustion,  when  once  com- 
menced, would  be  practically  instantaneous,  constituting  an 
explosion.  This  is  what  happens  in  coal-mines  when  the 
gas  issuing  from  fissures  in  the  coal  becomes  mingled  with 
the  air  in  the  right  proportions,  and  then  the  process  of 
combustion  is  commenced  by  the  lamp  of  the  miner  rais- 
ing a  portion  of  the  mixture  to  the  right  temperature  for 
the  combination  to  begin. 


THE    LOOSE-HOLDER   AND   THE    STRONG-HOLDER.        263 

To  form  explosive  combinations  for  practical  use  —  in 
blasting  rocks,  for  example,  or  for  fire-arms — we  require 
some  substance  in  a  solid  form,  as  gases  are  too  bulky  for 
transportation,  or  even  for  easy  management  when  we 
have  them  at  hand. 

Now  oxygen  can  not  exist  in  a  solid  form  except  when 
in  combination  with  some  other  substance.  The  thing  re- 
quired then,  obviously,  is  to  find  it  in  a  solid  form  com- 
bined with  some  substance  that  holds  it  most  loosely,  and 
will  most  readily  give  it  up  for  the  purpose  of  combustion. 
That  is  the  philosophy  of  gunpowder.  The  saltpetre  is  the 
substance  that  contains  the  oxygen,  holding  it,  however,  so 
loosely  that  it  very  readily  gives  it  up.  The  sulphur,  which 
inflames  at  a  low  temperature,  begins  the  work  of  combina- 
tion with  it  when  the  spark  is  applied,  and  the  charcoal, 
which  in  the  act  of  combination  gives  out  great  heat,  com- 
pletes the  work.  If  the  gunpowder  is  burnt  under  press- 
ure, as  it  is  when  it  is  tamped  into  the  rock  or  rammed 
into  a  gun,  the  intense  heat,  acting  upon  the  compressed 
gases  produced  by  the  combustion,  develop  the  vast  force 
that  is  produced  by  the  explosion. 

Thus  in  almost  all,  or,  at  least,  in  a  great  many  detona- 
ting, fulminating,  and  explosive  substances,  the  secret  is  a 
supply  of  oxygen  close  at  hand  for  rapid  combination  with 
a  combustible,  the  supply  being  contained  in  some  solid 
substance  in  which  the  oxygen  is  held  in  combination 
with  an  element  that  holds  it  by  a  very  weak  affinity,  so 
as  to  be  ready  at  any  moment  to  let  it  go.  The  element 
which  has  most  frequently  this  function  to  perform  is  ni- 
trogen, which  seems  to  be  a  great  loose-holder  in  the  econ- 
omy of  nature,  as  oxygen  is  a  great  strong-holder. 

There  are  many  other  kinds  of  chemical  action,  it  is 
true,  that  are  so  sudden  and  violent  as  to  produce  explo- 
sive effects  besides  those  in  which  oxygen  is  the  principal 


264 


SCIENTIFIC    TERMS    EXPLAINED. 


c 


EXPLOSION  IN   A   FOTJNDEBY. 


agent,  and  chemical  laboratories  are  subject  sometimes  to 
very  serious  accidents  when  substances  of  this  kind  are 
accumulated  in  them  in  large  quantities.  One  of  the  most 
serious  accidents  of  this  kind  occurred  only  the  last  year 
in  Paris  by  an  explosion  in  a  laboratory  in  the  midst  of  the 
city,  from  the  effects  of  which  many  persons  were  killed 
and  great  damage  was  done. 

SPECIFIC   HEAT. 

Another  very  remarkable  principle  in  regard  to  the  ac- 
tion of  heat  is  to  be  observed  in  the  fact  that  it  requires 
very  different  quantities  of  heat  to  raise  the  same  weight 
of  different  substances  to  the  same  temperature.  Bring  a 
pound  of  water  and  a  pound  of  marble  from  the  cool  air 
out  of  doors  into  a  warm  room,  and  it  is  found  that  the 
water  will  take  in  five  times  the  quantity  of  heat  in  com- 
ing up  to  the  temperature  of  the  room  that  the  marble 
will  require.  It  will  absorb  about  ten  times  as  much  as 


mill 


M 


SPECIFIC    HEAT.  267 

iron,  and  about  thirty  times  as  much  as  lead.  One  would 
suppose  that  the  same  quantity  of  heat  would  raise  the 
same  quantity  of  different  substances  to  the  same  temper- 
ature, but  the  fact  is  far  otherwise.  There  is  no  corre- 
spondence at  all  in  the  effect  produced,  whether  we  con- 
sider the  weight  or  the  bulk  of  the  substances  compared. 
Mix  hot  and  cold  water  together  in  equal  weights,  and  the 
mixture  will  be  of  exactly  an  intermediate  temperature. 
So  with  hot  and  cold  mercury.  But  mix  cold  water  and 
hot  mercury,  and  the  water  will  scarcely  be  warmed  at  all, 
on  account  of  the  small  quantity  of  heat  which  the  mercury 
requires  to  make  it  hot. 

That  constitution  of  a  body  on  which  the  quantity  of 
heat  which  it  requires  to  raise  its  temperature  depends  is 
called  its  specific  heat.  The  specific  heat  of  water  is  very 
high ;  that  of  iron  about  one  tenth  that  of  water ;  that  of 
silver  one  half  that  of  iron;  that  of  copper  only  one  fifth 
that  of  silver.  The  cause  of  these  differences  is  a  great 
mystery. 

Of  course,  the  amount  of  heat  which  these  substances 
absorb  in  being  raised  to  a  given  temperature  is  given  out 
again  when  they  are  cooled,  and  this  furnishes  an  easy 
mode  of  comparing  the  specific  heats  of  different  sub- 
stances by  observing  how  much  heat  they  give  out  in  be- 
ing cooled.  One  curious  way  of  determining  this  is  by 
seeing  how  much  ice  they  will  melt.  Suppose  several 
balls  of  different  metals,  but  of  the  same  weight,  are  put 
into  an  oven  and  heated  all  alike.  They  are  then  several- 
ly put  into  holes  made  in  a  block  of  ice,  and  covered  with 
another  block  of  ice  placed  above  in  the  manner  shown  in 
section  in  the  engraving  on  the  following  page. 

After  remaining  till  they  are  cold,  the  water  which  each 
one  has  produced  by  the  liquefaction  of  the  ice  is  taken 
out  and  weighed,  and  in  this  way  the  comparative  amount 


268 


SCIENTIFIC   TEEMS    EXPLAINED. 


THE   ICE-CIIE8T. 


of  heat  which  was  derived  from  the  cooling  of  the  several 
balls  from  the  temperature  of  the  oven  to  that  of  melted 
ice — namely,  32° — is  exactly  ascertained. 

This  difference  in  the  specific  heat  of  different  metals  is 
sometimes  shown,  for  illustration,  by  means  of  wax  instead 
of  ice.  A  number  of  small  balls  of  different  metals  are 
heated  in  a  vessel  of  water,  being  thus  all  raised  to  the 
same  temperature.  They  are  then  taken  out  and  placed 
upon  the  circular  cake  of  wax,  as  shown  in  the  engraving. 

It  will  be  found  in  such  a  case  that,  though  the  balls 
were  all  of  the  same  temperature  when  taken  from  the 


THE  CAKE  OF  WAX. 


PHILOSOPHY    OF   FOOT-WAEMEES.  269 

water,  some  have  heat  enough  in  them,  to  melt  their  way 
through  the  cake  of  wax  and  fall  down  upon  the  floor, 
while  others,  whose  capacity  for  heat  is  less,  have  only 
imbibed  enough  from  the  water  to  melt  their  way  partly 
through  the  cake  of  wax,  when  their  farther  progress  is  ar- 
rested by  the  failure  of  the  supply  they  had  in  store. 

Water  has  a  very  great  capacity  for  heat  compared  with 
most  other  substances.  For  this  reason,  a  bottle  of  hot 
water  is  an  excellent  thing  to  put  to  the  feet  of  a  sick  per- 
son to  keep  them  warm  during  the  night,  inasmuch  as  the 
water  has  a  larger  quantity  of  heat  in  store  than  most  oth- 
er substances  of  the  same  weight  would  have  if  heated  to 
the  same  temperature.  It  contains  about  five  times  the 
quantity  that  could  be  stored  in  an  equal  weight  of  mar- 
ble. How  it  is  with  soapstone  I  do  not  know.  The  way 
to  ascertain,  or,  at  least,  one  way  to  do  it,  would  be  to  heat 
a  block  of  soapstone,  and  also  an  equal  weight  of  water,  to 
the  same  degree  in  an  oven,  and  then,  by  placing  them  both 
in  holes  made  in  ice,  observe  which  melts  the  greatest  quan- 
tity of  the  ice  in  becoming  cooled. 

HEAT   OF   LIQUEFACTION. 

There  is  another  very  remarkable  phenomenon  connect- 
ed with  the  action  of  heat,  which  is  not  only  very  curious, 
but  is  of  fundamental  importance  to  be  understood.  It  is 
this,  that  what  is  called  the  heat  of  liquefaction — by  which 
is  meant  the  heat  that  is  absorbed  and  becomes  latent  in 
changing  a  body  from  the  solid  to  the  liquid  state — is  very 
different  in  quantity  for  different  substances.  It  requires 
one  hundred  and  forty  units  of  heat  to  the  pound  to  liquefy 
water,  for  example,  all  of  which  quantity  disappears  as  heat 
in  the  process,  and  is  employed  as  a  force  to  maintain  the 
water  in  its  liquid  state.  But  to  liquefy  lead  only  seven 
units  to  the  pound  is  required.  It  is  true  that  lead  does 


270  SCIENTIFIC   TERMS    EXPLAINED. 

not  begin  to  liquefy  until  it  has  reached  a  much  higher 
temperature  than  is  necessary  for  water,  but  when  it  has 
reached  that  temperature  and  begins  to  melt,  it  absorbs  a 
much  smaller  quantity  in  the  process  of  melting. 

This  difference  is  very  perceptible  in  fact  to  common 
observation.  For  lead,  when  it  begins  to  melt,  melts  very 
fast,  while  ice  melts  slowly,  on  account  of  its  requiring  so 
much  more  heat  to  make  the  internal  change ;  and  so 
lead  solidifies  again  much  more  rapidly  than  water,  as  it 
requires  only  the  abstraction  of  seven  units  of  heat  to  the 
pound,  whereas  one  hundred  and  forty  units  —  that  is, 
twenty  times  as  much — must  be  drawn  off  for  the  water. 
If  a  boy  melts  a  pound  of  lead  in  a  ladle,  and  draws  it 
back  from  the  fire  a  little  way,  it  all  hardens  very  rapidly ; 
but  it  takes  a  long  time  for  a  pound  of  water  to  freeze, 
even  though  it  is  put  in  a  place  as  much  colder  than  its 
point  of  congelation  as  the  air  around  the  ladle  was  colder 
than  the  point  of  congelation  of  the  lead. 

Thus  each  substance  requires  its  own  special  quantity 
of  heat  to  liquefy  it,  the  amount  being  very  different  for 
different  substances;  but  for  the  same  substance,  under 
the  same  circumstances,  it  is  always  rigidly  the  same. 

DIATHERMANCY. 

Lawrence  might  have  included  this  word  among  those 
hard  to  be  remembered  that  he  taught  the  boys.  It  bears 
the  same  relation  to  heat  that  transparency  does  to  light ; 
that  is  to  say,  that  as  the  word  transparency  denotes  that 
property  of  a  body  which  allows  light  to  pass  through  it, 
diathermancy  is  that  which  allows  heat  to  pass  through 
it.  We  may  say,  in  fact,  that  while  the  word  transpa- 
rency means,  etymologically,  shining  through,  diatherman- 
cy means  warming  through. 

We  have  a  general  idea  that  those  substances  which  are 


A   TRAP   TO    CATCH    SUNBEAMS.  271 

transparent  are  also  diathermant,  but  it  is  not  so  in  all 
cases  by  any  means.  A  plate  of  glass,  for  instance,  held 
between  your  face  and  a  stove,  will  allow  the  light  to  pass 
freely,  but  will  intercept  nearly  all  the  heat — that  is,  you 
can  see  the  stove  through  it  nearly  as  well  as  through  the 
air,  but  you  will  not  feel  the  warmth  through  it. 

And  yet  the  plate  of  glass  which  intercepts  the  heat 
from  the  stove  will  allow  the  heat  from  the  sun  to  pass 
through  it  very  freely.  And  this  is  found  to  be  owing,  not 
to  a  diiference  in  the  intensity  of  the.  heat,  but  in  some 
mysterious  difference  in  the  kind  or  quality  of  it.  The 
rays  of  bright  heat  from  the  sun  are  called  luminous  rays. 
The  rays  of  dark  heat  from  a  stove  not  red-hot  are  called 
obscure  rays.  There  are  found  to  be  very  curious  differ- 
ences in  the  action  of  these  different  rays,  which  lead  some- 
times to  very  remarkable  and  very  important  results. 

For  instance,  in  a  conservatory,  or  in  a  gardener's  hot- 
bed, or  a  room  with  windows  toward  the  south,  or  any 
other  such  inclosure  with  access  to  it  through  glass  for  the 
rays  of  the  sun,  the  air  inside  will  become  much  warmer 
than  that  surrounding  it  on  the  outside,  because  the  lumin- 
ous rays  can  come  in  through  the  glass.  But  when  they 
strike  the  ground  they  are  absorbed  and  warm  the  ground, 
and  then,  when  the  ground  begins  to  emit  a  radiation,  the 
rays  are  obscure  rays,  and  so  can  not  go  out  through  the 
glass.  Thus  the  heat  is  caught  in  a  trap,  as  it  were,  and 
imprisoned. 

If,  therefore,  in  the  spring,  you  put  a  box,  open  at  top 
and  bottom,  over  some  seeds  that  you  have  planted  in  your 
garden,  and  put  a  pane  of  glass  over  the  top,  you  literally 
set  "  a  trap  to  catch  sunbeams"  for  the  benefit  of  your 
seeds. 

It  is  very  certain  that  the  conditions  in  the  internal  con- 
stitution of  a  substance  on  which  the  transmission  of  light 


272  SCIENTIFIC   TEEMS    EXPLAINED. 

depends  are  very  different  from  those  which  favor  the  trans- 
mission of  heat.  Rock  salt,  for  example,  and  alum,  are  near- 
ly transparent,  but  a  plate  of  rock  salt  of  a  certain  thick- 
ness— one  tenth  of  an  inch — will  allow  almost  the  whole 
of  the  heat  to  pass  with  the  light,  while  the  alum,  without 
stopping  the  light,  will  intercept  almost  the  whole  of  the 
heat.  The  salt  will  transmit  nine  tenths,  and  the  alum 
only  one  tenth  of  it.  A  plate  of  water,  so  to  speak,  such  as 
may  be  formed  by  filling  the  space  between  two  thin  plates 
of  glass  placed  a  third  of  an  inch  apart,  will  intercept  a 
very  large  portion  of  the  heat,  though  it  is  almost  com- 
pletely transparent  in  respect  to  light. 

On  the  other  hand,  black  glass,  and  a  mineral  called 
smoky  quartz,  will  allow  nearly  all  the  heat  to  pass  through 
them,  while  they  almost  entirely  intercept  the  light. 

There  are  a  great  many  other  curious  facts  connected 
with  the  subject  of  diathermancy  which  greatly  interest 
all  those  who  have  the  time  and  opportunity  to  make  them- 
selves acquainted  with  them.  They  bring  to  view  distinc- 
tions in  heat  analogous  to  those  of  color  in  light.  These 
"  heat  tints,"  as  they  are  called,  are  abundantly  proved, 
though  they  do  not  affect  our  senses  directly.  We  have 
no  senses  adapted  to  be  affected  by  them.  But  there  is  no 
presumption  against  the  idea  that  other  animals,  and  espe- 
cially insects,  may  have  such  senses.  And  this  may  possi- 
bly be  a  key  to  the  mystery  of  the  numerous  inexplicable 
members  and  organs  which  many  insects  and  other  animals 
of  the  invertebrate  classes  possess,  and  of  many  strange 
and  otherwise  unaccountable  phenomena  presented  to  us 
in  their  habits,  instincts,  and  modes  of  life.  Heat  and  other 
radiations  from  the  sun,  imperceptible  to  us,  may,  in  their 
various  forms  and  conditions,  be  as  fruitful  and  as  varied  a 
source  of  sensations  to  them  as  light  is  to  us  in  its  endless 
metamorphoses. 


PLAY   A   NECESSITY   FOE   CHILDREN.  273 


CHAPTER  XXVIII. 

THE    SEA-BIKDS. 
/ 

SPECIAL  provision  is  often  made,  on  board  the  great  At- 
lantic steamers,  to  furnish  the  children  that  may  be  on 
board  with  means  and  facilities  for  play.  This  is  very  im- 
portant. Indeed,  one  of  the  first  necessities  for  children 
while  they  are  growing,  whether  on  land  or  at  sea,  is 
plenty  of  play.  Work,  although,  considered  as  exercise,  it 
might,  perhaps,  be  regarded  as  much  the  same  thing,  will 
not  really  answer  the  same  purpose.  The  reason  is  that 
work  brings  into  action  only  the  muscular  system,  while  it 
is  equally  important  to  exercise,  and  so  aid  in  developing, 
the  functions  of  the  nervous  system  and  the  brain. 

Study,  it  is  true,  serves  to  call  into  action  the  nervous 
system  and  the  brain,  but,  as  it  is  ordinarily  exacted,  it 
does  not  do  this  in  the  gentle  and  agreeable  manner  neces- 
sary for  producing  the  best  effect  in  respect  to  the  healthy 
development  of  the  embryo  powers.  In  order  that  -chil- 
dren may  grow  well,  and  secure  a  healthy  and  symmetri- 
cal development  of  all  their  powers,  they  must  have  plenty 
of  play. 

But  play,  important  as  it  is,  is  by  no  means  all  that  they 
require.  There  are  certain  powers  and  faculties  of  the 
mind  which  are  not  much  exercised  in  play,  and  which  yet 
must  be  exercised  in  order  that  the  progress  of  their  de- 
velopment may  keep  pace  with  the  growth  and  advance- 
ment of  the  system  in  other  respects.  Now  this  class  of 
faculties  can  only  be  called  into  action  by  study — that  is, 
by  thought  and  reflection.  Thus  we  see  that  the  object 
M2 


274  THE    SEA-BIRDS. 

of  study  for  young  persons  is  not  merely  the  acquisition  of 
knowledge.  There  is  a  still  greater  advantage  derived 
from  it  when  it  is  properly  pursued,  in  promoting  the  de- 
velopment and  growth  of  the  higher  powers  and  faculties 
of  the  mind. 

In  respect  to  the  number  and  variety  of  the  plays  which 
can  be  made  available  on  board  ship,  the  range  is  some- 
what limited  on  account  of  the  motion.  Rolling  nine-pins, 
for  example,  would  be  utterly  impossible  at  sea.  So  would 
any  kind  of  game  of  ball,  or  battledoor  and  shuttlecock. 
Any  thing  like  pitching  quoits,  too,  would  be  out  of  the 
question,  on  account  of  the  damage  which .  such  games 
would  do  to  the  decks. 

There  are  various  games,  however,  which  can  be  played 
without  encountering  these  difficulties.  The  sailors  usual- 
ly rig  up  a  swing  somewhere,  when  there  are  children  on 
board  that  desire  it ;  and  there  is  a  game  of  tossing  rings, 
which  consists  in  seeing  how  many  rings  out  of  a  dozen 
you  can  make  catch  over  a  short  iron  bar  set  up  in  an  up- 
right position  in  the  middle  of  a  small,  square  piece  of 
plank.  The  boys  and  girls,  too,  often  play  "  I  spy,"  run- 
ning about  the  decks,  and  seeking  for  hiding-places  behind 
the  masts  and  rigging,  or  dodging  about  among  the  set- 
tees, and  chairs,  and  camp-stools  occupied  by  the  passen- 
gers on  the  decks.  As  it  is  not  possible  for  the  children 
to  go  "out  of  doors"  to  play  when  they  are  on  board  a 
steam-ship  in  the  middle  of  the  Atlantic,  all  reasonable  pas- 
sengers are  very  indulgent  in  allowing  them  great  liberty 
in  coming  with  their  play  to  the  places  where  they  are 
talking  or  reading,  even  though  it  should  now  and  then 
cause  them  some  interruption. 

One  evening,  near  the  end  of  the  voyage — it  was,  in  fact, 
when  the  steamer  was  approaching  the  Irish  coast — the 
boys  and  girls  had  been  playing  upon  the  deck  for  some 


LEARNING   TO    DRAW.  275 

time,  when  John  observed  that  his  cousin  Lawrence,  who 
was  seated  by  himself  near  the  stern,  had  his  paper  and 
pencil  out,  and  seemed  to  be  drawing  something.  John 
was  standing  at  this  time  with  a  boy  named  Lionel,  and  a 
girl  named  Louise,  near  the  great  sky-light,  during  a  pause 
in  the  play. 

"  Let's  go  and  see  what  my  cousin  Lawrence  is  doing," 
said  he ;  "  he  is  making  some  kind  of  a  picture,  but  there  is 
nothing  that  I  see  but  water  and  sky  for  him  to  draw." 

"  Yes,"  said  Louise, "  there  are  some  gulls.  Perhaps  he 
is  drawing  one  of  them." 

They  all  at  once  went  to  the  place  where  Lawrence  was 
sitting.  He  was,  indeed,  making  a  picture  of  a  gull  just  in 
the  act  of  swooping  down  to  pick  up  something  from  the 
surface  of  the  water. 

"  Is  it  a  fish,"  asked  Louise,  "that  he  is  trying  to  catch?" 

"  It  may  be  a  fish,"  replied  Lawrence, "  or  it  may  be 
something  that  he  can  eat  which  the  stewards  have  thrown 
over  from  what  was  left  at  the  table." 

These  gulls  go  out  to  the  distance  of  several  hundred 
miles  from  the  land,  and  follow  the  ships  and  steamers 
sometimes  for  a  long  distance,  watching  for  what  may  be 
thrown  overboard  by  the  sailors,  and  also,  probably,  for  the 
chance  of  catching  some  of  the  fishes  which  are  enticed 
into  following  the  vessel  by  the  same  temptation. 

Lawrence  was  very  skillful  in  the  use  of  his  pencil.  He 
had  begun  to  acquire  this  art  when  he  was  quite  young. 
His  first  attempts  were  somewhat  discouraging,  as  the  re- 
sults did  not  satisfy  him  at  all.  Most  children,  when  they 
find  that  they  can  not  make  pretty  pictures  at  once,  give 
up  in  despair.  But  Lawrence  said  to  himself, 

"  I  can  not  expect  to  be  able  to  make  good  pictures  till 
I  have  learned.  Others  can  learn,  and  why  can  not  I.  I 
mean  to  persevere." 


276  THE    SEA-BIRDS. 

And  he  did  persevere.  From  time  to  time,  when  he  had 
leisure,  he  practiced  drawing.  First  he  copied  pictures  of 
buildings  from  engravings  in  books,  and  then,  as  he  ac- 
quired more  skill,  he  took  for  his  models  figures  of  men 
and  of  animals,  which  were  much  more  difficult. 

The  three  children  stood  a  few  minutes  looking  over 
Lawrence  at  his  work,  when  Lionel  at  length  asked  what 
the  gulls  were  doing. 

"  They  are  taking  in  their  coal,"  said  Lawrence,  gravely. 

"  Hoh  !"  exclaimed  Lionel, "  they  can't  eat  coal !" 

Lionel  thought  that  what  Lawrence  meant  was  that  the 
gulls  were  picking  up  bits  of  coal  from  the  cinders,  and 
other  refuse  from  the  furnace,  that  the  men  were  throwing 
overboard  from  time  to  time. 

"  No,"  said  Lawrence ;  "  and  perhaps  I  ought  not  to  say 
exactly  that  they  are  taking  in  their  coal,  for  they  are  not 
doing  that  literally.  They  are  taking  in  that  which  serves 
the  same  purpose  for  them  that  coal  does  for  our  engines. 
It  would  be  more  strictly  correct  to  say  that  they  are  tak- 
ing in  their  fuel." 

"  Come,  Louise,"  said  Lionel, "  let's  go  and  play." 

"  No,"  replied  Louise, " I  am  going  to  stay  and  see  Mr. 
Lawrence  finish  the  bird." 

"  Then  you  come,  John,"  said  Lionel. 

"  No,"  replied  John, "  I  am  going  to  stay  too." 

John  was  influenced  t>y  two  considerations  in  deciding 
to  stay.  One  was  his  wish  to  be  with  Louise,  and  the  other 
he  desired  to  have  Lawrence  explain  what  he  meant  by  the 
gull's  taking  in  fuel.  As  for  Louise,  she  was  a  charming 
girl,  and  was  a  great  favorite  among  all  the  boys  and  girls 
on  board,  not  only  on  account  of  her  beauty  and  accom- 
plishments, but  also,  and  more  especially,  on  account  of  her 
gentle  and  affectionate  disposition,  and  for  the  kind  regard 
which  she  manifested  for  the  welfare  and  happiness  of  the 


LEARNING   TO   UEAW. 


GULLS   TAKING   IN   FUEL.  279 

others.  If  any  difficulty  or  trouble  occurred,  she  always 
contrived  some  way  to  remedy  or  to  remove  it.  If  any 
body  seemed  to  be  neglected,  she  paid  them  attention,  or 
if  hurt,  she  helped  and  comforted  them.  She  was  a  very 
pretty  girl  too,  and  was  always  very  neatly  and  prettily 
dressed. 

John  was  interested,  moreover,  in  what  Lawrence  had 
begun  to  say  about  the  gull  being  employed  in  taking  in 
fuel,  because  he  knew  something  about  fuel  as  a  source  of 
power,  and  was  very  naturally  desirous  of  hearing  more. 
Lionel  knew  nothing  whatever  on  that  subject,  and  was, 
accordingly,  not  curious  about  it.  Louise  was  not  curious 
about  that  either,  but  she  wished  to  remain  in  order  to  see 
Mr.  Wollaston  draw. 

"  I  don't  know  that  I  ought  really  to  call  it  fuel,"  said 
Lawrence,  "  that  the  gulls  are  taking  in,  for,  in  common 
parlance,  we  only  apply  that  term  to  substances  which,  in 
developing  heat  and  power  by  combining  with  oxygen,  do 
it  with  so  much  violence  of  action  as  to  produce  incan- 
descence— that  is  to  say,  fire.  What  the  gulls  take  into 
their  stomachs  from  the  water  corresponds  to  the  coal  put 
into  the  furnaces  in  three  cardinal  points. 

"1.  It  consists  of  carbon,  hydrogen,  and  other  substances 
which  have  been  deoxydized  by  the  power  of  the  sun  in 
the  leaves  of  plants. 

"  2.  The  essential  change  which  takes  place  in  these  sub- 
stances within  the  bodies  of  the  birds  is  the  reoxydizing  of 
them,  and  the  setting  free  in  this  way  the  heat  and  force 
which  was  originally  stored  in  them  by  the  sun.  And, 

"  3.  All  the  warmth  in  the  bodies  of  the  birds,  and  all 
the  prodigious  strength  which  they  display  in  their  long 
flights  or  in  their  swooping  plunges  at  their  prey,  comes 
from  this  reoxydizing  of  this  food,  or  of  portions  of  the 
tissues  of  their  bodies  formed  from  it,  just  as  all  the  heat 


280  THE    SEA-BIRDS. 

in  the  furnaces  and  chimneys  of  the  ship,  and  all  the  force 
by  which  the  ship  itself  is  propelled  over  the  sea,  comes 
from  the  force  stored  in  the  coal,  and  liberated  by  the  re- 
oxydizing  of  it  in  the  fire." 

Lawrence  had  explained  this  principle  before,  in  relation 
to  other  animals,  in  his  conversations  with  John,  but  John 
was  only  prepared  on  that  account  to  be  the  more  inter- 
ested in  it  in  its  application  to  the  case  of  the  sea-bird, 
which  exerts  so  enormous  a  strength  in  proportion  to  its 
size,  and  which  requires  so  sure  and  constant  a  supply  of 
warmth  under  the  continued  and  extreme  exposure  it  must 
undergo  from  wintry  winds  and  driving  storms  far  out  at 
sea,  where  there  is  no  possibility  of  shelter. 

"In  a  philosophical  point  of  view,"  continued  Lawrence, 
"  there  is  only  this  difference  between  the  manner  in  which 
the  ship  and  the  bird  receive  their  heat  and  their  power, 
and  that  is  that  in  the  body  of  the  bird  the  reoxydation 
of  food  is  effected  by  a  process  that  is  comparatively  gen- 
tle, while  in  that  of  fuel  in  the  furnaces  of  the  ship  it  is 
very  violent  and  intense.  The  whole  amount  of  heat  and 
of  power  developed  by  the  oxydation  of  a  given  quantity 
of  the  material  is  precisely  the  same  in  both  cases,  only 
when  it  is  used  as  fuel  the  amount  is  given  out  in  a  briefer 
period,  and  so  is  more  intense." 

"  But,  Lawrence,"  said  John,  when  his  cousin  had  made 
these  explanations,  "if  the  food  which  animals  take  is  only 
a  kind  of  fuel  for  them  to  give  heat  and  force  by  its  being 
reoxydized  in  their  bodies,  why  won't  any  common  fuel  do 
for  them  for  food  ?  Why  can't  they  eat  wood  and  coal,  as 
well  as  meat  and  corn  ?" 

"  Because  their  machinery  is  not  adapted  to  it,"  replied 
Lawrence.  "  Different  kinds  of  machinery  are  adapted  to 
different  kinds  of  sustenance.  The  furnaces  of  this  ship 
are  adapted  to  burn  English  coal,  which  is  the  bituminous 


LAWRENCE'S  SKETCH.  281 

kind ;  in  America  they  are  often  arranged  for  anthracite 
coal  or  for  wood.  And  not  only  so,  but  the  engines  and 
all  the  machinery  are  fitted  to  be  driven  by  heat  and  by 
force  in  the  form  in  which  they  are  developed  by  combus- 
tion^ whereas  the  muscles,  and  nerves,  and  all  the  other 
internal  machinery  of  the  animal  system  are  fitted  to  be 
worked  by  heat  and  force  in  the  form  in  which  they  are 
furnished  by  the  process  of  digestion" 

John  was  interested  in  these  remarks  of  Lawrence  be- 
cause he  already  knew  enough  to  understand  them.  But 
Louise  did  not  understand  them  very  well,  and  so  she  did 
not  pay  so  much  attention  to  them,  but  stood  looking  at 
Lawrence's  work.  He  drew  several  gulls  in  different  po- 
sitions, as  they  plunged  toward  the  water,  or  just  skimmed 
the  surface  of  it,  or  rose  again  into  the  air.  Just  as  he  had 
finished  saying  to  John  what  is  related  above,  it  happened 
that  one  of  the  stewards  threw  out  a  wisp  of  hay  or  straw 
which  he  had  perhaps  taken  from  an  empty  Champagne- 
basket,  and,  as  the  wisp  floated  astern,  two  gulls  alighted 
upon  it  together,  and  Lawrence  immediately  began  to' 
sketch  the  group.  Louise  asked  him  to  give  that  picture 
to  her  when  it  was  finished.  Lawrence  said  he  would  do 
so,  and  that  he  would,  moreover,  finish  it  for  her  with 
special  care. 

"I  wish  I  could  draw,"  said  Louise. 

"  Well,"  replied  John,  "  you  can  easily  learn." 

"No,"  rejoined  Lawrence,  "not  easily.  She  can  learn, 
but  not  easily.  It  is  not  a  quick  or  an  easy  thing  to  learn 
to  draw." 

"  It  takes  a  great  deal  of  time  and  pains,  I  suppose," 
said  John. 

"  Not  exactly  so,"  replied  Lawrence.  "  It  takes  a  great 
deal  of  time  and  pleasure — that  is  to  say,  according  to  my 
experience." 


282  THE    SEA-BIRDS. 

"I  should  like  to  learn,"  said  Louise;  "and  I  would 
learn  if  I  had  any  body  to  teach  me." 

"  You  don't  need  any  body  to  teach  you,"  replied  Law- 
rence. "  All  you  have  to  do  is  to  make  a  little  book  of 
common  paper,  not  ruled,  and  when  you  are  at  leisure,  in- 
stead of  sitting  still  and  wishing  that  you  had  something 
to  do,  take  your  pencil  and  copy  parts  of  pictures  out  of 
any  picture-book  as  well  as  you  can." 

"  Why  not  whole  pictures  ?"  asked  Louise. 

"  It  is  very  well  to  take  whole  pictures,"  said  Lawrence, 
"if  your  object  is  to  show  off,  and  let  other  people  see  what 
you  can  do,  and  get  praised  for  it.  But  if  your  object  is  to 
learn,  you  had  better  take  at  first  only  parts  of  pictures, 
such  as  a  gate,  a  steep  bank,  a  boat,  one  side  of  a  house,  or 
even  a  door  or  a  window.  In  this  way  you  can  study  the 
lesson  better." 

"  Study  the  lesson  ?"  repeated  Louise,  not  knowing  ex- 
actly what  Lawrence  meant. 

"  I  mean  by  that,"  replied  Lawrence,  "  study  the  draw- 
ing, or  part  of  the  drawing  that  you  are  going  to  copy,  so 
as  to  see  by  what  kind  of  strokes  or  touches  particular  ef- 
fects are  produced." 

Louise  did  not  reply  to  this,  but  in  her  heart  she  resolved 
that  she  would  make  a  little  book  and  try. 

"  If  you  do  this,  and  persevere,"  said  Lawrence,  "  you 
will  make  a  great  deal  of  progress  in  cultivating  your  eye 
and  in  practicing  your  hand,  and  then,  when  you  finally 
see  any  person  who  knows  how  to  draw  well,  he  will  give 
you  some  advice  and  instruction  that  you  will  be  prepared 
to  understand  and  profit  by." 

"  I  mean  to  do  it,"  said  Louise. 

"Yes,"  replied  Lawrence,  "you  mean  to  do  it,  but  I  don't 
really  think  you  will ;  at  least  I  should  not  think  so  if  you 
were  a  boy." 


TIRED    OF   LEARNING.  283 

11  Why  not  ?"  asked  Louise. 

"  Because  boys,"  said  Lawrence,  "  though  they  are  will- 
ing to  try  hard  and  to  work  very  perseveringly  to  learn 
any  thing  that  is  useless,  commonly  get  tired  very  quick 
if  it  is  any  thing  useful.  They  will  practice  incessantly, 
of  their  own  accord,  in  order  to  learn  to  walk  on  stilts,  but 
they  are  very  seldom  seen  trying  voluntarily  to  learn  to 
write.  They  get  off  from  their  music-lesson  whenever  they 
can,  but  there  is  no  end  to  the  patience  and  perseverance 
they  show  in  learning  to  catch  a  ball,  or  to  manipulate 
jackstones,  or  to  acquire  any  other  utterly  useless  accom- 
plishment." 

"  But,  Lawrence,"  said  John,  "  I  don't  think  these  things 
are  utterly  useless." 

"  True,"  replied  Lawrence,  "  perhaps  they  are  not  utter- 
ly useless,  but,  at  any  rate,  dexterity  in  them  is  not  likely 
to  be  quite  so  useful  in  future  life  as  skill  in  music  or  draw- 
ing." 


284  OXYGEN    AND    THE    TELEGRAPH. 


CHAPTER  XXIX. 

OXYGEN   AND   THE    TELEGRAPH. 

"  IT  is  very  curious,"  said  Lawrence,  as  John  and  Louise 
sat  by  him,  one  on  each  side,  upon  the  settee,  overlooking 
his  drawing — "indeed,  it  is  wonderful  how  large  a  propor- 
tion of  the  work  that  is  done  and  the  effects  that  are  pro- 
duced in  the  world  results  from  the  reoxydation  of  sub- 
stances which  have  been  previously  deoxydized — that  is, 
from  the  force  with  which  oxygen  seizes  again  substances 
from  which  it  has  been  separated.  For  instance,  there  is 
the  action  of  the  electric  telegraph.  Did  you  know,  Louise, 
that  there  was  a  wire  under  us  here  at  the  bottom  of  the 
sea  that  is  conveying  messages  back  and  forth  between 
Europe  and  America  ?" 

"  I  knew  that  there  was  a  wire  somewhere,"  said  Louise, 
"  but  I  did  not  know  that  it  was  under  us  here." 

"  I  don't  know  myself  that  it  is  exactly  under  us  at  this 
spot,"  said  Lawrence,  "  but  it  can  not  be  very  far  from  us, 
for  we  are  drawing  near  to  the  coast  of  Ireland,  and  at  a 
place  not  a  great  way  from  where  the  wire  leaves  the 
shore." 

"  How  far  down  is  it,  through  the  water,"  asked  Louise, 
"  to  where  the  wire  is  lying  ?" 

"  From  half  a  mile  to  a  mile,  I  suppose,"  said  Lawrence, 
"  though  I  do  not  know  exactly  the  depth.  The  curious 
thing  about  it,  as  I  was  saying  to  you,  John,  is  that  the 
source  of  the  power  by  which  the  telegraph  is  worked  is 
substantially. the  same,  in  its  nature,  with  that  by  which 
the  engines  of  the  ship  are  driven — namely,  the  intense 


WHERE   THE    POWER   COMES    FROM.  285 

energy  with  which  oxygen  rushes  to  a  reunion  with  a  sub- 
stance that  has  previously  been  separated  from  it.  In  the 
case  of  the  steam-engines,  the  substance  is  carbon,  or,  rath- 
er, a  combination  of  hydrogen  and  carbon ;  in  the  case  of 
the  telegraph,  it  is  zinc. 

"  There  are  two  differences,  however,  in  the  two  cases. 
First,  in  the  case  of  the  carbon  and  hydrogen,  the  oxygen 
was  originally  separated  from  them  by  the  heat  and  chem- 
ical action  of  the  sun  in  the  leaves  of  plants,  while  it  was 
separated  from  the  zinc  by  the  heat  and  chemical  action 
of  the  fire  in  the  furnace  in  which  the  zinc  was  smelted 
from  the  ore ;  and,  secondly,  the  force  resulting  from  the 
reoxydation  of  the  hydrocarbon  appears  as  mechanical  mo- 
tion, while  that  coming  from  the  zinc  is  in  the  form  of  elec- 
trical energy.  The  force  is  prodigious  in  both  cases.  In 
the  one,  it  turns  paddle-wheels  with  so  much  power  as  to 
drive  an  immense  ship,  with  all  its  machinery,  and  passen- 
gers, and  cargo,  at  great  speed  through  the  stormiest  seas ; 
in  the  other,  it  sends  a  succession  of  electrical  impulses 
every  second  through  three  thousand  miles  of  wire  at  the 
bottom  of  the  sea." 

"I  never  could  understand  very  well  how  they  could 
send  messages  by  the  telegraph,"  said  Louise. 

"  I  will  explain  it  to  you,"  said  Lawrence.  "  I  can  ex- 
plain it  so  that  you  can  understand  it  pretty  well — at  least 
so  far  as  to  have  a  general  idea  of  the  principle.  But  I 
must  make  a  picture  of  it  first." 

So  saying,  Lawrence  laid  aside  his  pictures  of  the  birds, 
and,  taking  another  piece  of  paper,  he  proceeded  to  make 
a  drawing  of  the  instrument  by  which  telegraphic  messa- 
ges are  received.  He  did  it  quite  rapidly,  describing  the 
several  parts  as  he  went  on. 

"  But  first,"  he  said, "  you  must  understand  one  very  re- 
markable fact  on  which  the  whole  action  of  the  telegraph 


286  OXYGEN   AND   THE    TELEGRAPH. 

depends,  and  that  is  that  you  can  make  a  bar  of  iron 
strongly  magnetic  in  an  instant,  at  any  time,  by  passing  an 
electric  current  through  a  wire  wound  around  it ;  then,  by 
stopping  the  current,  the  magnetism  will  almost  instant- 
ly cease.  It  is  no  matter  how  far  off  the  battery  may 
be  which  produces  the  current.  The  electricity  may  be 
brought  any  distance  by  means  of  wires,  and,  as  it  may  be 
sent  in  series  of  impulses  longer  or  shorter,  and  combined 
in  any  way,  the  operators  can  make  an  iron  bar  pull  as  a 
magnet,  and  let  go  its  hold  alternately,  just  as  they  please, 
no  matter  at  what  distance  it  may  be  from  them.  So  you 
see  all  that  they  have  to  do  is  to  agree  upon  a  certain 
mode  of  pulling  and  letting  go  for  every  letter  of  the  al- 
phabet, in  order  to  enable  them  to  spell  out  any  words  or 
any  messages  they  please." 

Here  Lawrence  made  upon  the  margin  of  his  paper  a  lit- 
tle drawing  of  a  bar  of  iron,  bent  somewhat  in  the  shape 
of  a  horseshoe,  with  a  wire  round  it,  and  a  cross-bar  of  iron 
with  a  weight  suspended  from  it,  and  held  there  by  the  at- 
traction. 

"The  electric  current  is  passing  round  now,"  he  said, 
"  and  that  makes  the  iron  strongly  magnet- 
ic. If  one  of  the  wires  were  separated  from 
the  magnet,  the  magnetism  would  cease  in 
an  instant,  and  the  weight  would  drop." 

The  chief  force  of  a  magnet,  as  the  reader 
probably  knows  already,  is  manifested  at  the 
two  extremities,  which  are  called  the  poles ; 
and  the  bar  which  is  wound  with  the  wire, 
and  is  to  be  made  magnetic,  is  bent  in  this 
form  so  as  to  bring  the  two  poles  together, 
in  order  that  they  may  help  each  other  in 

.       .  . 

the  lifting.    A  magnet  made  in  this  form  is 
called  a  horseshoe  magnet.     And  if  the  magnetism  is  pro- 


THE  TELEGRAPHIC  APPAEATUS. 


287 


duced  by  a  current  of  electricity  carried  round  it  in  a  coiled 
wire,  it  is  called  an  electro-magnet. 

Having  thus  explained  the  general  principle  on  which 
the  system  operates,  Lawrence  described  the  several  parts 
of  the  apparatus,  pointing  them  out  upon  the  drawing 
which  he  had,  in  the  mean  time,  been  making.  He  made  it 
from  recollection,  having  seen  such  an  engraving  in  a  book. 
His  drawing  was  well  calculated  to  give  a  clear  idea  of  the 
general  principle  on  which  the  telegraph  is  worked,  though 
the  apparatus  is,  in  fact,  much  more  complicated  than  was 
represented  in  it ;  and  it  varies,  moreover,  very  much  in  its 
form  in  different  places  where,  telegraphs  are  in  operation. 

You  can  obtain  a  good  idea  of  the  drawing  which  Law- 
rence made,  and  of  the  principle  on  which  the  telegraph 
operates,  by  this  engraving.  The  long  and  narrow  band, 


ACTION  OP  THE  TELEGRAPH. 


jt>,  which  comes  down  in  the  direction  of  the  arrow  on  the 
left,  and  then,  after  passing  through  the  machine,  goes  up 
the  slide,  and  so  down  in  the  direction  marked  by  the  sec- 
ond arrow  on  the  right,  is  the  paper  on  which  the  message 
is  marked.  It  is  drawn  down  through  the  machine  by  two 


288  OXYGEN   AND   THE    TELEGRAPH. 

rollers  between  which  it  passes,  and  which  are  made  to  re- 
volve slowly  all  the  time,  while  the  machine  is  in  opera- 
tion, by  the  clock-work  which  you  see  in  the  central  and 
lower  part  of  the  apparatus.  All  the  use  of  that  clock- 
work is  simply  to  draw  the  band  of  paper  along,  in  a  slow 
and  steady  manner,  as  it  receives  the  marks  which  form 
the  message,  and  which  are  all  made  by  the  simple  mechan- 
ism on  the  left. 

The  marks  by  which  the  message  is  spelled  out  consist 
simply  of  dots  and  dashes.  Thus  a  dot  and  a  dash,  like 
these,  .  — ,  mean  ay  a  dash  and  three  dots,  thus,  — . . .  b, 
and  so  with  all  the  other  letters,  the  simplest  combinations 
being  assigned  to  the  letters  most  frequently  used.  These 
marks  are  all  made  upon  the  band  of  paper  as  it  is  slowly 
drawn  along  by  the  rollers.  They  are  made  by  the  little 
pencil  seen  at  s.  If  this  pencil  merely  touches  the  paper 
and  is  at  once  withdrawn,  it  makes  a  dot.  If  it  is  pressed 
against  the  paper,  and  held  so  for  a  moment  while  the  pa- 
per is  drawn  along  a  little  way,  it  of  course  makes  a  dash. 

And  now  for  the  manner  in  which  the  pencil  is  made  to 
be  alternately  pressed  against  the  paper  and  withdrawn 
from  it.  You  will  see,  by  looking  at  the  engraving,  that  it 
is  fixed  at  the  end  of  a  somewhat  long  bar,  /,  which  bar  is 
poised  upon  a  pivot  near  the  middle  of  it  at  d.  At  the 
outer  end  is  a  cross-piece,  a,  and  it  is  plain  that  when  that 
cross-piece  is  drawn  down,  the  pencil  end  will  be  pushed 
up ;  and  as  long  as  the  cross-bar  is  held  down,  the  pencil 
will  continue  to  make  a  trace  upon  the  band  of  paper  as 
the  band  is  drawn  along  above  it. 

Now  directly  under  the  cross-bar  are  the  two  poles  of 
the  horseshoe  magnet,  m  m,  with  the  two  wires  below 
which  form  the  connection  with  the  electrical  battery,  per- 
haps hundreds  of  miles  away.  Of  course,  when  the  opera- 
tor at  the  distant  station  makes  the  connection,  and  sends 


ORIGIN    OF    DISCOVERY.  289 

an  electrical  current  through  the  wire,  the  electro-magnet 
becomes  magnetized,  the  cross-bar  is  drawn  down,  the  pen- 
cil is  pressed  up,  and  a  dot  or  a  dash  is  made  upon  the  pa- 
per, according  to  the  length  of  the  time  during  which  the 
electrical  current  is  allowed  to  flow.  Thus  the  operator, 
by  sending  a  succession  of  electrical  impulses  of  longer  or 
shorter  duration,  can  cause  any  succession  of  dots  and 
dashes  he  pleases  to  be  made  upon  the  long  paper  band, 
although  he  may  be  himself  hundreds  or  even  thousands 
of  miles  away.  .' 

"  So  you  see,"  continued  Lawrence,  after  he  had  finished 
his  explanation  of  his  drawing, "  that  if  we  could  go  down 
to  the  bottom  of  the  sea,  where  the  telegraphic  wire  is  ly- 
ing, and  could  examine  it,  and  if  we  had  senses  that  were 
of  the  right  kind,  and  were  sufficiently  acute  to  enable  us 
to  perceive  what  is  going  on  upon  it,  all  that  we  should 
find  would  be  a  series  of  electrical  impulses,  some  longer 
and  some  shorter,  running  with  immense  velocity  along  it, 
from  America  to  Ireland,  or  from  Ireland  to  America. 

"And  the  curious  thing  about  it,  John,"  continued  Law- 
rence, "  is  that  the  source  from  which  all  these  electrical 
impulses  are  derived  is  the  same  that  we  have  seen  origi- 
nating power  in  so  many  other  ways — that  is,  the  devour- 
ing energy  of  oxygen ;  only  what  he  devours  in  this  case  is 
zinc  instead  of  carbon  and  hydrogen. 

"  And  there  is  one  thing  curious  for  you,  Louise,  in  the 
way  in  which  it  was  found  out  that  a  current  of  electrici- 
ty, in  passing  through  a  wire  wound  round  an  iron  rod  or 
bar,  would  make  it  suddenly  a  magnet.  A  philosopher 
who  was  making  some  experiments  one  day  observed  ac- 
cidentally that  when  a  current  of  electricity  passed  along 
a  wire  over  a  magnetic  needle,  it  caused  it  to  turn  in  a  very 
singular  manner.  Many  people  might  have  thought  that 
no  possible  good  could  come  from  such  an  apparently  in- 

N 


290  OXYGEN   AND   THE    TELEGRAPH. 

significant  fact  as  this,  and  would  not  have  investigated  it. 
But  those  who  first  observed  this  phenomenon  did  not  think 
so.  There  were  many  persons  among  them  who  became 
much  interested  in  investigating  it.  They  ascertained  be- 
fore long,  among  a  great  many  other  things,  that  an  elec- 
trical current  carried  round  a  bar  of  iron  would  make  it  a 
magnet,  and  that  the  magnetism  would  suddenly  cease  as 
soon  as  the  current  was  interrupted ;  and  the  whole  sci- 
ence of  telegraphy  has  grown  out  of  this  discovery. 

"So  you  see  the  best  thing  for  us  to  do  is  to*  learn  every 
thing  we  can.  We  never  can  foresee  in  how  many  ways 
knowledge  will  be  useful  to  us.  I  never  thought,  when  I 
was  learning,  to  draw,  that  I  was  procuring  myself  the 
pleasure  of  one  day  making  pictures  to  amuse  and  instruct 
you  and  John  on  board  a  steamer  crossing  the  Atlantic." 

Lawrence  now  said  that  it  was  drawing  near  to  the  time 
for  tea,  and  so  he  rose  from  his  seat  to  go  below.  John 
and  Louise  remained  upon  the  settee.  A  moment  after- 
ward Lionel  and  some  other  children  came  up  to  propose 
a  plan  for  having  a  game  on  the  decks  the  next  morning 
before  breakfast.  Just  at  the  same  time  the  major  came 
along,  and  stood  there  a  moment  listening  to  their  talk 
about  it. 

"  Only  I  can't  come  before  the  first  bell  rings,"  said  Li- 
onel. "My  mother  is  not  willing;  she  says  the  decks  are 
wet." 

"  And  we  can't  hear  the  first  bell,"  said  Louise,  "  in  our 
state-room,  it  is  so  far  off." 

"Then  I'll  come  and  tell  you  when  it  rings,"  said  John, 
"  and  guide  you  up ;  and  you  must  be  on  my  side  in  the 
game." 

"  No,"  said  Lionel,  "  I  want  Louise  to  be  on  my  side ; 
won't  you,  Louise  ?" 

Louise  looked  somewhat  perplexed  at  being  the  object 


LIONEL   AND    LOUISE.  291 

of  this  rivalry,  and  seemed  hardly  to  know  what  to  say. 
At  length  she  answered  timidly,  "Whichever  of  you  come 
for  me." 

"Good  !"  said  Lionel;  "I'll  be  sure  to  be  there." 

"Only  you  must  not  come  before  the  first  bell  rings," 
said  Louise ;  "I  can't  come  out  till  then." 

So  it  was  agreed  that  Louise  was  to  come  with  the  one 
who  was  ready  to  wait  upon  her.  They  also  asked  the 
major  whether  he  thought  there  was  a  prospect  of  a  pleas- 
ant morning. 

"Yes,"  said  he,  "an  excellent  prospect.  But  if  you  make 
appointments,  any  of  you,  and  expect  to  keep  them,  I  advise 
you  to  look  sharp  about  the  time,  for  we  shall  make  the 
land  some  time  during  the  night,  and  when  we  do  we  shall 
very  likely  jump  to  Greenwich  time." 

So  saying,  the  major  walked  away. 

"  What  does  he  mean  ?"  asked  Lionel. 

«  Why,  I'll  tell  you,"  said  John.     "  You  see—" 

"  I  don't  care  about  knowing,  after  all,"  interrupted  Li- 
onel. "  It  is  all  about  navigation,  I  suppose,  and  I  don't 
expect  ever  to  be  a  sea-captain." 

So  saying,  he  walked  away,  and  the  bell  just  then  begin- 
ning to  ring,  the  whole  party  went  down  to  tea. 


292  JUMPING   TO    GREENWICH    TIME. 


CHAPTER  XXX. 

JUMPING   TO    GREENWICH   TIME. 

JOHN  knew  perfectly  well  what  the  major  meant  by  the 
"jumping  to  Greenwich  time,"  which  he  supposed  would 
take  place  as  soon  as  the  steamer  should  make  the  land. 
Inasmuch,  as  has  already  been  explained,  the  time  at  any 
part  of  the  earth's  surface  is  determined  by  the  position 
of  the  sun  in  relation  to  it,  of  course,  in  going  from  place 
to  place  in  an  easterly  or  westerly  direction,  the  clock  must 
be  changed  from  day  to  day,  because  the  sun  arrives  earlier 
at  a  place  lying  to  the  eastward,  and  later  at  a  place  lying 
to  the  westward ;  therefore,  in  going  to  the  eastward,  the 
clock  must  be  put  forward  every  day,  and  in  going  to  the 
westward,  backward.  Going  to  the  northward  or  to  the 
southward  of  course  makes  no  difference. 

They  generally,  at  sea,  make  the  change  in  the  ship's 
time  for  each  day  at  noon,  both  for  the  convenience  of  do- 
ing it  at  that  hour,  and  also  because  noon  is  the  time  when 
the  officers  make  the  principal  observations  and  calcula- 
tions on  which  the  determining  of  the  ship's  place  depends. 
At  no  other  time  of  the  day  do  they  ascertain  so  exactly 
where  they  are.  So  they  set  the  clocks  at  noon,  according 
to  the  time  of  the  place  where  they  are  then,  and  go  on 
with  that  time  till  the  next  day  at  noon,  when  they  deter- 
mine their  new  position,  and  change  the  clocks  to  the  new 
time. 

Of  course,  the  time  is  really  changing  gradually  all  the 
while  as  the  vessel  moves  onward ;  but,  as  they  can  not 
conveniently  make  the  clocks  keep  pace  with  the  change, 


.GREENWICH    TIME.  293 

and  as,  moreover,  they  do  not,  during  the  interval,  deter- 
mine their  position,  they  let  them  go  on  until  the  new  po- 
sition is  determined  on  the  following  day,  and  then  move 
them  forward  or  set  them  back  all  at  once  by  a  leap,  as  it 
were,  to  the  new  time. 

But  when  they  make  the  land,  as  they  call  it — that  is, 
come  in  sight  of  it — they,  of  course,  know  precisely  where 
they  are,  and  can  adopt  the  time  of  the  place  at  once,  if 
they  choose. 

Now  England  not  being  very  wide  from  east  to  west, 
the  difference  of  time  in  the  different  portions  of  it  and  of 
the  adjacent  waters  is  not  very  great,  and  it  is  found  con- 
venient for  many  purposes  to  use  Greenwich  time — that 
is,  the  time  of  the  great  central  observatory  at  Greenwich, 
near  London — in  every  part  of  the  kingdom  ;  and  thus  it 
happens  that  ships,  on  approaching  the  land  —  often,  it 
seems,  as  soon  as  they  come  in  sight  of  the  shore  —  set 
their  clocks  at  once  to  Greenwich  time. 

John  did  not  know  this,  but  as  soon  as  the  major  made 
the  remark  referred  to  in  the  last  chapter,  he  understood 
at  once  what  he  meant.  Immediately  after  tea  he  went 
down  into  his  state-room  and  looked  at  the  map  to  ascer- 
tain how  many  degrees  of  longitude  there  were  between 
the  meridian  of  Greenwich  and  the  position  of  the  ship,  as 
near  as  he  could  determine  it  by  estimate,  that  day  at  noon. 
He  found  the  distance  was  twelve  or  fifteen  degrees. 

"  It  must  make  a  difference  of  nearly  an  hour,"  he  said 
to  himself. 

He  knew  that  the  proportion  was  one  hour  for  every  fif- 
teen degrees.  For,  there  being  three  hundred  and  sixty 
degrees  in  the  whole  circumference  of  the  earth,  and  twen- 
ty-four hours  in  the  day,  a  simple  process  of  division  will 
show  that  the  sun  must  pass  over  fifteen  degrees  every 
hour. 


294  JUMPING   TO    GREENWICH   TIME. 

"So  I  must  look  out  for  the  first  bell,"  he  said  to  him- 
self, "  at  half  past  six  by  my  watch  to-morrow  morning, 
instead  of  half  past  seven." 

He  accordingly  went  at  once  up  to  the  saloon  to  inform 
Louise. 

"Why — are  we  going  to  have  the  breakfast  earlier?" 
asked  Louise. 

"  We  are  going  by  a  different  time,"  said  John.  "  The 
clocks  are  going  now  by  the  time  of  the  place  we  were  at 
to-day  at  noon,  but  as  soon  as  we  get  into  English  waters 
we  shall  go  by  a  jump  to  English  time." 

Louise  looked  puzzled.  She  had  heard  of  "jumping  into 
next  week,"  but  whether  this  phrase  of  jumping  to  English 
time  was  a  joke  like  that,  or  what  it  was,  she  could  not  tell. 

"I  don't  understand  it  very  well,"  said  she;  "but  never 
mind,  I'll  be  ready." 

Accordingly,  the  next  morning,  John  rose  and  dressed 
himself  when  it  was  only  six  by  his  watch.  When  it  was 
near  half  past  six,  he  made  his  way  through  several  long 
corridors  to  the  door  of  Louise's  state-room.  He  had  not 
been  there  but  a  few  minutes  when  the  door  was  slowly 
opened — a  little  crack,  and  he  saw  Louise's  eyes  peeping 
out. 

"John,"  said  a  gentle  voice,  in  a  whisper,  "are  you 
there  ?" 

"Yes,"  said  John  ;  "all  ready." 

"  Has  the  first  bell  rung  ?" 

"  Not  yet,"  said  John  ;  "  but  I  expect  it  every  minute." 

"  Then  I  must  wait  a  little,"  said  Louise,  and  she  shut 
the  door.  In  a  very  few  minutes  the  bell  rang,  and  then 
Louise  immediately  came  out,  and  she  and  John  went  up 
to  the  deck. 

They  found  a  considerable  number  of  the  girls  and  boys 
assembling  there,  though  several  of  them,  not  understand- 


295 

ing  about  the  change  of  time,  were  still  asleep  in  their 
berths. 

The  air  was  mild  and  balmy,  the  decks  were  dry,  and, 
more  than  all  the  rest,  the  land  was  in  full  view.  They 
were  all  so  much  interested  in  looking  at  the  land  that  it 
was  some  time  before  they  began  their  play.  When  at 
length  they  were  ready  to  begin,  there  were  enough  for 
an  excellent  game,  and  an  excellent  game  they  had. 

All  this  time  Lionel  lay  snug  in  his  berth.  He  heard 
the  first  bell,  it  is  true,  and  aroused  himself  enough  to  look 
at  his  watch,  but,  finding  that  it  was  only  about  half  past 
six,  he  concluded  that  it  was  some  other  bell,  and  lay  down 
and  went  to  sleep  again.  At  length  he  was  aroused  by  the 
second  bell,  and,  dressing  himself  hastily,  he  ran  along  the 
passage-ways  to  the  state-room  of  Louise.  He  knocked 
gently  at  the  door.  Louise's  mother  opened  it.  He  asked 
whether  Miss  Louise  was  ready. 

"  Oh,  she  has  gone  up  on  deck  long  ago,"  said  the  lady. 

Lionel  turned  away  and  hurried  back  along  the  passage- 
ways to  go  on  deck,  saying,  "  It  can't  be  long  ago,  certain- 
ly, for  it  is  not  five  minutes  since  the  bell  rang." 

To  his  utter  astonishment,  as  soon  as  he  reached  the  head 
of  the  stairs  leading  to  the  saloon,  he  found  the  people  all 
going  in  to  breakfast — groups  of  girls  and  boys  here  and 
there  among  them,  their  faces  flushed  and  beaming  with 
excitement  and  pleasure. 

"What  does  this  mean?"  said  he  to  one  of  the  stewards, 
who  was  carrying  in  a  great  urn  filled  with  coffee ;  "  it  is 
not  breakfast-time — it  is  only  half  past  seven." 

"Ah !  we  are  on  Greenwich  time  now,"  said  the  steward. 
So  saying,  he  pressed  on,  and  was  lost  in  the  crowd. 

It  is  very  true,  as  Lawrence  said,  that  it  is  best  for  us  to 
learn  all  we  can,  for  there  is  no  foreseeing  in  how  many 


296  JUMPING    TO    GREENWICH    TIME. 

ways  knowledge  of  any  kind  may  prove  to  be  of  use  to  us. 
Who  would  have  thought  that  the  enjoyment  of  an  hour 
of  play,  and  the  possession  of  a  charming  partner  in  it, 
could  have  depended  upon  a  boy's  understanding  the  re- 
lation between  difference  of  longitude  and  difference  of 
time  ! 


LAND    IX    SIGHT.  297 


CHAPTER  XXXI. 

_END     OF    THE     VOYAGE. 

IT  was  the  land  forming  the  southwestern  coast  of  Ire- 
land that  first  came  in  sight.  It  appeared  in  the  horizon 
like  a  low  cloud,  within  an  hour  of  the  expected  time,  and 
precisely  in  the  expected  direction,  so  accurate  had  been 
the  guidance  of  the  steamer  across  the  pathless  waste  of 
waters. 

For  many  hours  the  passengers  sat  upon  the  decks  watch- 
ing the  promontories,  and  cliffs,  and  light-houses  that  came 
successively  into  view  as  they  sailed  swiftly  along  the 
coast.  The  air  was  mild  and  balmy,  although  the  region 
is  quite  far  to  the  north.  The  warmth  made  it  very  agree- 
able to  be  on  deck,  and  it  was  interesting  to  reflect  that  a 
considerable  portion  of  it  had  descended  from  the  sun  in 
the  tropics  months  before,  and  had  been  brought  to  the 
northward  in  the  waters  of  the  Gulf  Stream. 

It  is  curious  to  think  how  very  little  heat  there  is  de- 
veloped on  the  surface  of  the  earth  which  we  can  not  trace 
very  readily,  though  often  indirectly,  to  the  sun.  All  that 
heat  that  comes  from  the  combustion  of  wood  and  coal — 
in  the  fires  in  our  houses,  the  furnaces  of  the  manufacto- 
ries, and  that  which,  acting  under  the  boilers  of  steam-en- 
gines, propels  ships  at  sea  and  trains  on  land — all  comes, 
as  we  have  already  seen,  from  the  sun  ;  for  this  heat  is  only 
the  liberation  of  that  stored  up  in  the  vegetable  organiza- 
tion by  the  sun  while  the  plant  from  which  the  fuel  was 
derived  was  growing.  All  the  force  exerted  by  men  and 
animals,  as  was  shown  in  the  case  of  the  gulls,  comes  in 
the  same  way,  namely,  from  the  reoxydation  within  the 


298  END    OF    THE    VOYAGE. 

system  of  substances  deoxidized  by  the  action  of  the  sun 
in  the  leaves  of  the  plants  which  produced  the  fruit  or  the 
grain  which — either  directly,  or  through  the  flesh  of  ani- 
mals in  which  the  deoxydized  substances  were  preserved — 
served  them  for  food.  Thus  the  food  which  an  animal  con- 
sumes is  really  the  fuel  which  drives  his  mental  and  phys- 
ical machinery,  for  the  force  is  deduced  from  it  in  the  same 
way  as  from  fuel,  namely,  by  the  reoxydizing  of  elements 
which  had  previously  been  deoxydized  by  the  power  of  the 
sun. 

In  the  same  manner,  all  the  heat  that  is  produced  by  fric- 
tion comes  originally  from  the  sun,  for  the  force  which  pro- 
duces the  friction  is  derived  from  that  source.  A  boy 
strikes  fire  with  a  flint  and  steel.  The  spark  is  a  spark  of 
light  and  heat  from  the  sun,  for  the  friction  which  produces 
the  heat  is  an  expenditure  of  force — that  is,  it  is  a  force 
converted  into  heat,  and  that  force  comes  from  the  muscles 
of  the  boy's  arm,  being  produced  there,  as  has  been  abun- 
dantly proved,  by  a  process  very  analogous  to  that  of  the 
combustion  which  evolves  force  for  impelling  the  steam- 
engine  ;  and  the  store  of  heat  which  is  thus  brought  out 
into  action  was  contained  in  the  food  which  he  ate — per- 
haps that  morning — in  which  food  the  force  was  originally 
stored  by  the  action  of  the  sun. 

Even  the  heat  developed  when  metals  are  burned  comes 
from  the  sun,  as,  for  example,  in  the  case  of  iron,  which  has 
been  already  described,  and  in  that  of  other  metals  which 
can  also  be  burned,  though  in  some  cases  peculiar  precau- 
tions have  to  be  taken  to  facilitate  the  continued  access  of 
oxygen  to  it.  Zinc,  for  instance,  when  made  incandescent, 
burns  at  the  surface,  but  it  soon  covers  itself  with  a  film 
which  shuts  off  the  oxygen  of  the  air  from  the  metal  be- 
low. But  if,  while  incandescent,  it  is  poured  out  into  the 
air,  it  burns  continuously  in  a  very  splendid  manner. 


COMBUSTION    OF   ZIXC. 


299 


OOMIJU8TION   OF   2LXO. 


In  all  tliese  cases,  even  those  of  burning  metals,  the  heat 
developed  may  be  traced  back  to  the  sun ;  for  the  metal 
was  found  in  the  earth  already  combined  with  oxygen,  and 
was  separated  from  it  by  artificial  means,  the  effective 
agency  in  which  was  heat  derived  from  the  combustion  of 
..wood  or  coal ;  so  that,  sooner  or  later,  wherever  we  see 
heat  or  force  in  action  upon  the  earth,  if  we  trace  it  back 
to  its  origin,  we  come  to  the  sun. 

There  are,  however,  some  exceptions.  There  is  heat  in 
the  interior  of  the  earth  which  we  can  not,  at  present  at 
least,  connect  with  that  origin.  As  we  descend  into  the 
interior  of  the  earth,  as,  for  instance,  in  mines,  we  find  a 
gradual,  but  very  regular  increase  of  temperature.  This 
heat  ultimately  becomes  very  great,  as  we  know  from  the 
heat  of  springs  of  water  which  come  up  sometimes  from 


300  END    OF   THE    VOYAGE. 

great  depths,  and  still  more  conclusively  from  the  erup- 
tions of  volcanoes.  The  force  and  violence  of  these  erup- 
tions are  probably  caused  by  the  expansive  force  of  steam, 
produced  from  water  which  insinuates  itself  to  the  heated 
region.  But  the  heat  itself,  although,  perhaps,  were  it  not 
for  the  intervention  of  water,  it  would  remain  constantly 
in  a  state  of  quiescence  and  repose,  must  be  exceedingly 
great,  both  in  quantity  and  intensity.  These  eruptions 
often  take  place  from  beneath  the  sea. 

Lawrence  and  his  friend  Miss  Almira  were  seated  to- 
gether on  the  deck  conversing  on  these  and  similar  sub- 
jects as  the  steamer  went  on  up  the  Channel  on  her  ap- 
proach toward  Queenstown,  where  she  was  to  stop  to  land 
the  mails  and  such  passengers  as  wished  to  land  in  Ireland. 
Lawrence  opened  a  book  which  he  had  been  reading,  and 
showed  Almira  a  picture  which  he  said  afforded  a  good  il- 
lustration of  what  he  had  been  saying.  It  was  a  picture 
of  a  ship  under  full  sail,  which  was  proceeding  on  its  way 
under  the  influence  of  a  gentle  wind  which  filled  its  sails, 
and  also  of  a  small  steamer  near,  which  was  going  on  its 
way  impelled  by  the  power  of  its  engine. 

"Here  is  an  illustration,"  said  Lawrence, "of  what  I  have 
been  saying.  The  sun,  by  its  heat,  produced  the  wind 
which  is  propelling  the  ship,  and  he  also,  ages  ago,  laid  up 
in  that  ancient  vegetation  the  force  which  the  coal  in  the, 
steamer  is  now  rendering  back  for  the  working  of  her-  en- 
gine. Thus  the  sun,  in  going  to  his  rest,  leaves  his  agents, 
the  wind  and  the  fire,  to  go  on  with  the  performance  of 
their  duty  while  he  is  gone,  in  the  exercise  of  strength 
which  he  has  himself  provided  for  them." 

Almira  seemed  much  interested  in  this  train  of  thought, 
but,  just  at  this  moment  happening  to  turn  her  head  so  as 
to  look  forward,  she  saw  a  small  steamer  directly  before 
them.  The  steamer  was  not  moving,  but  was  blowing  off 


THE    QUEENSTOWN   TUG. 


303 


THE   SUN   AND   HIS   WOBK. 


her  steam,  and  she  stood  directly  across  the  ship's  bows,  at 
the  distance  of  about  a  quarter  of  a  mile. 

"What  can  that  steamer  mean?"  said  Almira.  "We 
shall  run  over  her  if  she  does  not  get  out  of  the  way." 

"  That  must  be  the  Queenstown  tug,"  said  Lawrence ; 
"  she  is  waiting  for  us." 

"  Oh !  then  I  must  go  below  and  get  ready  to  land,"  said 
Almira ;  "  we  are  going  to  land  at  Queenstown." 

Lawrence  was  quite  surprised,  and  a  good  deal  disap- 
pointed to  hear  this,  as  he  had  hoped  that  Almira's  party 
were  going  onward  to  Liverpool,  and  that  he  should  have 
an  opportunity  to  call  and  see  her  at  their  hotel.  Almira 
rose,  and  Lawrence  accompanied  her  to  the  head  of  the 


304  END    OF   THE    VOYAGE. 

gangway  stairs,  expressing  his  regret  that  he  was  to  see 
her  no  more.  She  said  that  she  hoped  to  meet  him  again 
in  London,  or  Paris,  or  at  some  other  place  during  their 
tour,  and  that,  at  any  rate,  she  hoped  he  would  call  and 
see  her  in  New  York  on  his  return  to  America. 

"  Do  you  live  in  New  York  ?"  asked  Lawrence,  some- 
what surprised. 

"  Yes,"  said  she ;  "  and  I  will  give  you  my  card,  with  the 
address,  before  I  leave." 

So  saying,  she  went  down  the  gangway  to  find  her  father 
and  mother. 

In  the  mean  time  the  steamer  continued  to  advance  to- 
ward the  tug,  and  soon  began  to  turn  off  toward  the  right. 
The  tug,  too,  began  to  move  forward,  and  the  steamer,  tak- 
ing a  grand  sweep,  and  the  tug  advancing  to  accompany 
her,  they  were  soon  moving  together  in  nearly  parallel  di- 
rections, but  gradually  drawing  nearer  to  each  other. 
When  they  came  pretty  near  they  both  stopped  their  en- 
gines, but  continued  moving  on  under  the  impulse  which 
they  had  acquired.  The  steam-valves  were  opened,  for  it 
was  necessary  that  the  steam,  since  its  force  was  no  longer 
expended  in  driving  the  machinery,  should  be  allowed  to 
escape  into  the  air.  It  formed  trumpets  of  the  escape- 
pipes,  and  filled  the  air  with  such  a  loud  and  incessant 
roar  that  no  other  sound  could  be  heard. 

There  was  a  great  state  of  excitement  and  confusion  ev- 
ery where  on  board.  The  passengers  thronged  all  those 
portions  of  the  decks  that  were  on  the  side  toward  the 
tug.  A  vast  pile  of  trunks  and  baggage  had  been  accumu- 
lated near  the  place  for  the  gangway-plank,  where  an  open- 
ing had  been  made  in  the  bulwarks.  Stewards  were  con- 
tinually coming  with  more  trunks  to  add  to  the  accumula- 
tion. The  passengers  who  were  to  land,  and  those  who 
were  to  remain,  were  bidding  each  other  good-by — some 


PARTING    SCENES.  305 

by  shaking  hands  with  each  other  in  the  crowd,  and  some 
by  exchanging  nods  and  throwing  kisses  between  the  up- 
per deck  and  the  lower.  The  tremendous  roar  of  the  steam 
prevented  any  thing  from  being  heard, 
i  In  the  midst  of  this  scene  of  confusion  and  noise  Law- 
rence found  Almira,  and  she  introduced  him  to  her  father 
and  mother,  though  he  could  not  hear  the  names,  if,  indeed, 
she  mentioned  the  names  at  all.  $i)ie  also  took  out  a  card 
from  a  pretty  little  card-case  and  gave  it  to  him.  It  was 
too  dark  to  see  what  was  upon  it,  so  Lawrence  put  it  in 
his  portmonnaie  without  attempting  to  read  the  name. 

In  the  mean  time  the  tug  had  been  brought  up  to  the 
side  of  the  steamer  and  secured,  the  plank  had  been*  laid, 
and  a  long  line  of  men  were  passing  over  it  loaded  with 
bags,  trunks,  boxes,  and  every  other  species  of  baggage. 
When  this  work  was  completed,  the  passengers  wTho  were 
to  land  at  Queenstown  began  to  pass  down  to  the  deck  of 
the  tug.  When  they  were  all  on  board,  the  little  steamer 
seemed  full  to  overflowing,  all  the  space  that  was  left  by 
the  heaps  of  baggage  being  filled  with  passengers — some 
standing,  others  seated,  some  on  benches,  and  some  on 
trunks  and  baggage — all,  however,  looking  up  toward  the 
ship,  as  the  tug  moved  away,  and  waving  their  handker- 
chiefs in  response  to  the  farewell  wavings  of  those  on 
board. 

The  roaring  of  the  steam  in  the  steam-pipes  was  now 
suddenly  stopped,  and  the  great  steamer  began  to  move 
forward  again  on  her  way,  while  the  tug  was  lost  to  view 
in  the  obscurity. 

The  next  morning  Lawrence  and  his  party  landed  at 
Liverpool,  and  that  very  afternoon  Lawrence  went  out 
with  the  boys  to  buy  their  little  compasses.  He  found  a 
kind  of  ivory  pencil-case;  with  a  compass  at  the  upper  end 
of  it,  and  a  thermometer  at  the  side. 


306  END    OF   THE    VOYAGE. 

"  Oh,  what  a  cunning  little  thermometer !"  said  Flippy, 
when  he  saw  these  pencils.  "  That  is  the  most  splendid 
pencil-case  I  ever  -saw." 

"  How  should  you  like  them  for  your  compasses,  boys  ?" 
asked  Lawrence ;  "  you  see  there  is  a  compass  in  the  top." 

"  But  that  would  be  more  than  the  bargain,"  said  John. 
"It  was  only  a  compass  that  you  promised,  and  there  is  a 
thermometer  here  too." 

"Oh,  never  mind,"  said  Flippy;  "give  us  one  of  these 
pencils.  I'd  a  great  deal  rather  have  a  thermometer  too." 

"And  then  there  is  the  pencil  besides,"  said  John. 

"No  matter,"  said  Flippy;  "that  will  be  all  the  handier. 
We  can  write  with  our  pencil,  and  tell  the  points  of  the 
compass,  and  see  how  warm  it  is,  all  in  one." 

"  Very  well,"  said  Lawrence,  "  you  shall  have  them. 
You  were  both  very  good  boys  all  the  voyage,  and  it 
made  the  time  pass  a  great  deal  more  pleasantly  to  me 
having  you  on  board,  and  having  an  opportunity  to  teach 
you  something.  There  is  nothing  that  I  like  better  than 
to  teach  boys  that  like  to  learn" 


THE    END. 


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Illustrated  by  CLARENCE  DOBELL.  i6mo,  Cloth,  Gilt  Edges,  $1  oo. 

Children's  Picture  -  Books.  Square  4to,  about  300  pages  each, 
beautifully  printed  on  Tinted  Paper,  with  many  Illustrations  by  WEIR,  STEINLE, 
OVERBECK,  VEIT,  SCHNORR,  HARVEY,  and  others.  Bound  in  Cloth,  Gilt,  $i  50  a 
volume  ;  or  the  Series  complete,  in  neat  case,  $j  50 : 

The  Children's  Bible  Picture- Book.— The  Children's  Picture  Fable-Book.— 
The  Children's  Picture-Book  of  Quadrupeds  and  other  Mammalia.  —  The 
Children's  Picture-Book  of  the  Sagacity  of  Animals.— The  Children's  Picture- 
Book  of  Birds. 


Interesting  Books  for  the  Young. 


Harper's  Boys'  and  Girls'  Library.  32  Volumes.  Engravings. 
i8mo,  Cloth.  Sold  separately  at  75  cents  a  volume  : 

Lives  of  the  Apostles  and  Early  Martyrs. — The  Swiss  Family  Robinson,  2  vols. 
— Sunday  Evenings,  comprising  Scripture  Stories,  3  vols. — Mrs.  Hofland's 
Son  of  a  Genius. — Thatcher's  Indian  Traits,  2  vols. — Thatcher's  Tales  of  the 
American  Revolution. — Miss  Eliza  Robins's  Tales  from  American  History,  3 
vols. — Mrs.  Hofland's  Young  Crusoe  ;  or,  The  Shipwrecked  Boy. — Perils  of 
the  Sea. — Lives  of  Distinguished  Females. — Mrs.  Phelps's  Caroline  Wester- 
ley. — Mrs.  Hughs's  Ornaments  Discovered. — The  Clergyman's  Orphan  ;  the 
Infidel  Reclaimed. — Uncle  Philip's  Natural  History. — Uncle  Philip's  Eviden- 
ces of  Christianity.  —  Uncle  Philip's  History  of  Virginia.  —  Uncle  Philip's 
American  Forest. — Uncle  Philip's  History  of  New  York,  2  vols. — Uncle  Phil- 
ip's Whale  Fishery  and  the  Polar  Sea,  2  vols. — Uncle  Philip's  History  of  the 
Lost  Colonies  of  Greenland. — Uncle  Philip's  History  of  Massachusetts,  2  vols. 
— Uncle  Philip's  History  of  New  Hampshire,  2  vols. 

Harper's  Fireside  Library  :  expressly  adapted  to  the  Domestic 
Circle,  Sunday-Schools,  &c.  Cloth,  75  cents  each  : 

Alden's  Alice  Gordon. — Alden's  Lawyer's  Daughter. — Alden's  Young  School- 
mistress.— Burdett's  Arthur  Martin. — The  Dying  Robin. — Ellen  Herbert ;  or, 
Family  Changes. — Mayhew's  Good  Genius  that  turned  every  thing  into  Gold. 
— William  the  Cottager. — Mayhew's  Magic  of  Kindness. 

Harper's  Story  Books.  Narratives,  Biographies,  and  Tales  for 
the  Young.  By  JACOB  ABBOTT.  With  more  than  1000  beautiful  Engravings. 

"  HARPER'S  STORY  BOOKS"  can  be  obtained  complete  in  Twelve  Volumes, 
each  one  containing  Three  Stories,  at  the  price  of  $21  oo;  or  in  Thirty-six  Thin 
Volumes,  each  containing  One  Story,  at  the  price  of  $32  40.     The  volumes  sold 
separately,  the  large  ones  at  $i  75  each,  the  others  at  90  cents  each. 
Volume    I. — Bruno  ;  Willie  and  the  Mortgage  ;  The  Strait  Gate. 
"        II. — The  Little  Louvre  ;  Prank  ;  Emma. 
"      III. — Virginia  ;  Timboo  and  Joliba  ;  Timboo  and  Fanny. 
"       IV.— The  Harper  Establishment  ;  Franklin  ;  The  Studio. 
"        V.— The  Story  of  Ancient  History  ;  The  Story  of  English  History ;  The 

Story  of  American  History. 
VI.— John  True  ;  Elfred  ;  The  Museum. 

VII.— The  Engineer  ;  Rambles  among  the  Alps  ;  The  Three  Gold  Dollars. 
VIII.— The  Gibraltar  Gallery  ;  The  Alcove  ;  Dialogues.      . 
IX.— The  Great  Elm  ;  Aunt  Margaret ;  Vernon. 

X.— Carl  and  Jocko  ;  Lapstone  ;  Orkney  the  Peacemaker. 
XI. — Judee  Justin  ;  Minigo  ;  Jasper. 
XII.— Congo;  Viola;  Little  Paul. 
Some  of  the  Story  Books  are  written  particularly  for  Girls,  and  some  for  Boys ; 
and  the  different  volumes  are  adapted  to  various  ages,  so  that  the  Series  forms  a  com- 
plete Library  of  Story  Books  for  Children  of  the  Family  and  the  Sunday-School. 

Mayhew's  Boyhood  of  Martin  Luther ;  or,  The  Sufferings  of  the 
Little  Beggar- Boy  who  afterward  became  the  Great  German  Reformer.  Beauti- 
fully Illustrated.  i6mo,  Cloth,  $i  25. 

Mayhew's  Peasant-Boy  Philosopher.  The  Story  of  the  Peasant- 
Boy  Philosopher  ;  or,  "  A  Child  Gathering  Pebbles  on  the  Sea-Shore."  (Found- 
ed on  the  Early  Life  of  Ferguson,  the  Shepherd-Boy  Astronomer,  and  intended  to 
show  how  a  Poor  Lad  became  acquainted  with  the  Principles  of  Natural  Science.) 
Illustrations.  i6mo,  Cloth,  $i  25. 

Mayhew's  Wonders  of  Science  ;  or,  Young  Humphrey  Davy  (the 
Cornish  Apothecary's  Boy,  who  taught  himself  Natural  Philosophy,  and  eventu- 
ally became  President  of  the  Royal  Society).  The  Life  of  a  Wonderful  Boy  writ- 
ten for  Boys.  Illustrations.  i6mo,  Cloth,  $i  25. 

Mayhew's  Young  Benjamin  Franklin ;  or,  The  Right  Road  through 
Life.  A  Story  to  show  how  Young  Benjamin  Learned  the  Principles  which  Raised 
him  from  a  Printer's  Boy  to  the  First  Embassador  of  the  American  Republic.  A 
Boy's  Book  on  a  Boy's'  own  Subject.  With  Illustrations  by  JOHN  GILBERT. 
i6mo,  Cloth,  $i  25. 

Folks  and  Fairies.  Stones  for  Little  Children.  By  LUCY  RAN- 
DALL COMFORT.  Illustrated.  Square  4to,  Cloth,  $1  oo. 


Interesting  Books  for  the  Young. 


Mrs.  Mortimer's  Reading  without  Tears  ;  or,  A  Pleasant  Mode  of 
Learning  to  Read.  Beautifully  Illustrated.  Small  4to,  Cloth,  75  cents. 

Mrs.  Mortimer's  Reading  without  Tears,  Part  II.  Beautifully  Il- 
lustrated. Small  4to,  Cloth,  $1  25. 

Mrs.  Mortimer's  'Lines  Left  Out ;  or,  Some  of  the  Histories  left  out 
in  "  Line  upon  Line."  The  First  Part  relates  Events  in  the  Times  of  the  Patri- 
archs and  the  Judges.  With  Illustrations.  i6mo,  Cloth,  75  cents. 

Mrs.  Mortimer's  More  about  Jesus.  With  Illustrations  and  a 
Map.  i6mo,  Cloth,  75  cents. 

Mrs.  Mortimer's  Streaks  of  Light ;  or,  Fifty-two  Facts  from  the 
Bible  for  Fifty-two  Sundays  of  the  Year.  Illustrations.  i6mo,  Cloth,  Gilt,  75  cts. 

Harry's  Ladder  to  Learning.  With  250  Illustrations.  Square 
4to,  Cloth,  75  cents. 

Harry's  Summer  in  Ashcroft.  Illustrations.  Square  4to,  Cloth, 
75  cents. 

Kingston's  Fred  Markham  in  Russia ;  or,  The  Boy  Travellers  in 
the  Land  of  the  Czar.  By  W.  H.  G.  KINGSTON.  Profusely  and  elegantly  Illus- 
trated. Small  410,  Cloth,  Gilt,  75  cents. 

The  Adventures  of  Reuben  Davidger,  Seventeen  Years  and  Four 
Months  Captive  among  the  Dyaks  of  Borneo.  By  J-AMES  GREENWOOD.  With 
Engravings,  8vo,  Cloth,  $i  75. 

Wild  Sports  of  the  World  :  A  Book  of  Natural  History  and  Ad- 
venture. By  JAMES  GREENWOOD,  Author  of  "  The  True  History  of  a  Little  Rag- 
amuffin," "The  Seven  Curses  of  London,"  &c.  With  147  Illustrations.  Crown 
8vo,  Cloth,  $2  50. 

Self-Made  Men.     By  CHARLES  C.  B.  SEYMOUR.     Many  Portraits. 

izmo,  588  pages,  Cloth,  $i  75. 

Smiles's  Self- Help  :  with  Illustrations  of  Character  and  Conduct. 
By  SAMUEL  SMILES,  ismo,  Cloth,  $i  25. 

Thackeray's  Rose  and  the  Ring ;  or,  The  History  of  Prince  Giglio 
and  Prince  Bulbo.  A  Fireside  Pantomime  for  Great  and  Small  Children.  By  Mr. 
M.  A.  TITMARSH.  Numerous  Illustrations.  Small  4to,  Cloth,  $i  oo. 

Wood's  Homes  without  Hands  :  Being  a  Description  of  the  Hab- 
itations of  Animals,  classed  according  to  their  Principle  of  Construction.  By  J. 
G.  WOOD,  M.  A.,  F.L.S.,  Author  of  "  Illustrated  Natural  History."  With  about 
140  Illustrations,  engraved  on  Wood  by  G.  PEARSON,  from  Original  Designs  made 
by  F.  W.  KEYL  and  E.  A.  SMITH,  under  the  Author's  Superintendence.  8vo, 
Cloth,  Beveled,  $4  50. 

A  French  Country  Family.  Translated  by  the  Author  of  "  John 
Halifax"  from  the  French-  of  Madame  DE  WITT,  nee  GUIZOT.  Illustrations, 
lamo,  Cloth,  $i  50. 

Nineteen  Beautiful  Years  ;  or,  Sketches  of  a  Girl's  Life.  Written 
by  her  Sister.  With  an  Introduction  by  Rev.  R.  S.  FOSTER,  D.D.  i6mo,  Cloth, 
$i  oo. 

Hooker's  Child's  Book  of  Nature.  The  Child's  Book  of  Nature, 
for  the  Use  of  Families  and  Schools :  intended  to  aid  Mothers  and  Teachers  in 
Training  Children  in  the  Observation  of  Nature.  In  Three  Parts.  Part  I.  Plants. 
Part  II.  Animals.  Part  III.  Air,  Water,  Heat,  Light,  &c.  By  WORTHINGTON 
HOOKER,  M.D.  Engravings.  The  Three  Parts  complete  in  One  Volume,  Small 
4to,  Cloth,  $2  oo ;  or  separately,  90  cents  each. 

Mace's  History  of  a  Mouthful  of  Bread,  and  its  Effect  on  the  Or- 
ganization of  Men  and  Animals.  i2mo,  Cloth,  $i  75. 

Mace's  Servants  of  the  Stomach.  The  Servants-  of  the  Stomach. 
By  JEAN  MACE,  Author  of  "  The  History  of  a  Mouthful  of  Bread,"  "  Home  Fairy 
Tales,"  &c.,  &c.  Reprinted  from  the  London  Edition,  Revised  and  Corrected. 
i2mo,  Cloth,  $i  75. 

Miss  Warner's  Three  Little  Spades.     Illustrations.     i6mo,  Cloth, 

$1   00. 


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